diff --git a/.circleci/config.yml b/.circleci/config.yml
index 5b21ff3..d372540 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -59,9 +59,13 @@ jobs:
       - run:
           name: Add musl target
           command: rustup target add x86_64-unknown-linux-musl
+      # This can be removed when https://github.com/heroku/libcnb.rs/issues/407 is fixed.
+      - run:
+          name: Mark heroku/builder:22 as a trusted builder
+          command: pack config trusted-builders add heroku/builder:22
       - run:
           name: Run tests
-          command: RUST_BACKTRACE=1 cargo test --all-features --locked -- --include-ignored
+          command: cargo test --all-features --locked -- --include-ignored
       - save-cargo-cache
 
 workflows:
diff --git a/Cargo.lock b/Cargo.lock
index f3029ea..23642c2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -101,9 +101,9 @@ dependencies = [
 
 [[package]]
 name = "bumpalo"
-version = "3.9.1"
+version = "3.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4a45a46ab1f2412e53d3a0ade76ffad2025804294569aae387231a0cd6e0899"
+checksum = "37ccbd214614c6783386c1af30caf03192f17891059cecc394b4fb119e363de3"
 
 [[package]]
 name = "bytes"
@@ -113,9 +113,9 @@ checksum = "c4872d67bab6358e59559027aa3b9157c53d9358c51423c17554809a8858e0f8"
 
 [[package]]
 name = "camino"
-version = "1.0.7"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f3132262930b0522068049f5870a856ab8affc80c70d08b6ecb785771a6fc23"
+checksum = "869119e97797867fd90f5e22af7d0bd274bd4635ebb9eb68c04f3f513ae6c412"
 dependencies = [
  "serde",
 ]
@@ -274,9 +274,9 @@ dependencies = [
 
 [[package]]
 name = "filetime"
-version = "0.2.15"
+version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "975ccf83d8d9d0d84682850a38c8169027be83368805971cc4f238c2b245bc98"
+checksum = "c0408e2626025178a6a7f7ffc05a25bc47103229f19c113755de7bf63816290c"
 dependencies = [
  "cfg-if",
  "libc",
@@ -286,13 +286,11 @@ dependencies = [
 
 [[package]]
 name = "flate2"
-version = "1.0.23"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b39522e96686d38f4bc984b9198e3a0613264abaebaff2c5c918bfa6b6da09af"
+checksum = "f82b0f4c27ad9f8bfd1f3208d882da2b09c301bc1c828fd3a00d0216d2fbbff6"
 dependencies = [
- "cfg-if",
  "crc32fast",
- "libc",
  "miniz_oxide",
 ]
 
@@ -401,9 +399,9 @@ dependencies = [
 
 [[package]]
 name = "hashbrown"
-version = "0.11.2"
+version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
+checksum = "db0d4cf898abf0081f964436dc980e96670a0f36863e4b83aaacdb65c9d7ccc3"
 
 [[package]]
 name = "hermit-abi"
@@ -422,9 +420,9 @@ checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
 
 [[package]]
 name = "http"
-version = "0.2.6"
+version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "31f4c6746584866f0feabcc69893c5b51beef3831656a968ed7ae254cdc4fd03"
+checksum = "75f43d41e26995c17e71ee126451dd3941010b0514a81a9d11f3b341debc2399"
 dependencies = [
  "bytes",
  "fnv",
@@ -433,9 +431,9 @@ dependencies = [
 
 [[package]]
 name = "http-body"
-version = "0.4.4"
+version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ff4f84919677303da5f147645dbea6b1881f368d03ac84e1dc09031ebd7b2c6"
+checksum = "d5f38f16d184e36f2408a55281cd658ecbd3ca05cce6d6510a176eca393e26d1"
 dependencies = [
  "bytes",
  "http",
@@ -444,9 +442,9 @@ dependencies = [
 
 [[package]]
 name = "httparse"
-version = "1.7.0"
+version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6330e8a36bd8c859f3fa6d9382911fbb7147ec39807f63b923933a247240b9ba"
+checksum = "496ce29bb5a52785b44e0f7ca2847ae0bb839c9bd28f69acac9b99d461c0c04c"
 
 [[package]]
 name = "httpdate"
@@ -456,9 +454,9 @@ checksum = "c4a1e36c821dbe04574f602848a19f742f4fb3c98d40449f11bcad18d6b17421"
 
 [[package]]
 name = "hyper"
-version = "0.14.18"
+version = "0.14.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b26ae0a80afebe130861d90abf98e3814a4f28a4c6ffeb5ab8ebb2be311e0ef2"
+checksum = "42dc3c131584288d375f2d07f822b0cb012d8c6fb899a5b9fdb3cb7eb9b6004f"
 dependencies = [
  "bytes",
  "futures-channel",
@@ -510,9 +508,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "1.8.1"
+version = "1.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0f647032dfaa1f8b6dc29bd3edb7bbef4861b8b8007ebb118d6db284fd59f6ee"
+checksum = "6c6392766afd7964e2531940894cffe4bd8d7d17dbc3c1c4857040fd4b33bdb3"
 dependencies = [
  "autocfg",
  "hashbrown",
@@ -535,15 +533,15 @@ dependencies = [
 
 [[package]]
 name = "itoa"
-version = "1.0.1"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1aab8fc367588b89dcee83ab0fd66b72b50b72fa1904d7095045ace2b0c81c35"
+checksum = "112c678d4050afce233f4f2852bb2eb519230b3cf12f33585275537d7e41578d"
 
 [[package]]
 name = "js-sys"
-version = "0.3.57"
+version = "0.3.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "671a26f820db17c2a2750743f1dd03bafd15b98c9f30c7c2628c024c05d73397"
+checksum = "c3fac17f7123a73ca62df411b1bf727ccc805daa070338fda671c86dac1bdc27"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -556,9 +554,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.122"
+version = "0.2.126"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec647867e2bf0772e28c8bcde4f0d19a9216916e890543b5a03ed8ef27b8f259"
+checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
 
 [[package]]
 name = "libcnb"
@@ -651,9 +649,9 @@ checksum = "7fb9b38af92608140b86b693604b9ffcc5824240a484d1ecd4795bacb2fe88f3"
 
 [[package]]
 name = "log"
-version = "0.4.16"
+version = "0.4.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6389c490849ff5bc16be905ae24bc913a9c8892e19b2341dbc175e14c341c2b8"
+checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
 dependencies = [
  "cfg-if",
 ]
@@ -666,56 +664,36 @@ checksum = "a3e378b66a060d48947b590737b30a1be76706c8dd7b8ba0f2fe3989c68a853f"
 
 [[package]]
 name = "memchr"
-version = "2.4.1"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
+checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
 
 [[package]]
 name = "miniz_oxide"
-version = "0.5.1"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d2b29bd4bc3f33391105ebee3589c19197c4271e3e5a9ec9bfe8127eeff8f082"
+checksum = "6f5c75688da582b8ffc1f1799e9db273f32133c49e048f614d22ec3256773ccc"
 dependencies = [
  "adler",
 ]
 
 [[package]]
 name = "mio"
-version = "0.8.2"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52da4364ffb0e4fe33a9841a98a3f3014fb964045ce4f7a45a398243c8d6b0c9"
+checksum = "713d550d9b44d89174e066b7a6217ae06234c10cb47819a88290d2b353c31799"
 dependencies = [
  "libc",
  "log",
- "miow",
- "ntapi",
  "wasi 0.11.0+wasi-snapshot-preview1",
- "winapi",
-]
-
-[[package]]
-name = "miow"
-version = "0.3.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9f1c5b025cda876f66ef43a113f91ebc9f4ccef34843000e0adf6ebbab84e21"
-dependencies = [
- "winapi",
-]
-
-[[package]]
-name = "ntapi"
-version = "0.3.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c28774a7fd2fbb4f0babd8237ce554b73af68021b5f695a3cebd6c59bac0980f"
-dependencies = [
- "winapi",
+ "windows-sys",
 ]
 
 [[package]]
 name = "num-integer"
-version = "0.1.44"
+version = "0.1.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d2cc698a63b549a70bc047073d2949cce27cd1c7b0a4a862d08a8031bc2801db"
+checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
 dependencies = [
  "autocfg",
  "num-traits",
@@ -723,9 +701,9 @@ dependencies = [
 
 [[package]]
 name = "num-traits"
-version = "0.2.14"
+version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
+checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
 dependencies = [
  "autocfg",
 ]
@@ -742,9 +720,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.10.0"
+version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87f3e037eac156d1775da914196f0f37741a274155e34a0b7e427c35d2a2ecb9"
+checksum = "7709cef83f0c1f58f666e746a08b21e0085f7440fa6a29cc194d68aac97a4225"
 
 [[package]]
 name = "pathdiff"
@@ -780,9 +758,9 @@ dependencies = [
 
 [[package]]
 name = "pin-project-lite"
-version = "0.2.8"
+version = "0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e280fbe77cc62c91527259e9442153f4688736748d24660126286329742b4c6c"
+checksum = "e0a7ae3ac2f1173085d398531c705756c94a4c56843785df85a60c1a0afac116"
 
 [[package]]
 name = "pin-utils"
@@ -792,11 +770,11 @@ checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.37"
+version = "1.0.39"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec757218438d5fda206afc041538b2f6d889286160d649a86a24d37e1235afd1"
+checksum = "c54b25569025b7fc9651de43004ae593a75ad88543b17178aa5e1b9c4f15f56f"
 dependencies = [
- "unicode-xid",
+ "unicode-ident",
 ]
 
 [[package]]
@@ -809,9 +787,7 @@ dependencies = [
  "libherokubuildpack",
  "linked-hash-map",
  "regex",
- "tempfile",
  "thiserror",
- "ureq",
 ]
 
 [[package]]
@@ -875,9 +851,9 @@ dependencies = [
 
 [[package]]
 name = "rustls"
-version = "0.20.4"
+version = "0.20.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fbfeb8d0ddb84706bc597a5574ab8912817c52a397f819e5b614e2265206921"
+checksum = "5aab8ee6c7097ed6057f43c187a62418d0c05a4bd5f18b3571db50ee0f9ce033"
 dependencies = [
  "log",
  "ring",
@@ -885,17 +861,11 @@ dependencies = [
  "webpki",
 ]
 
-[[package]]
-name = "rustversion"
-version = "1.0.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2cc38e8fa666e2de3c4aba7edeb5ffc5246c1c2ed0e3d17e560aeeba736b23f"
-
 [[package]]
 name = "ryu"
-version = "1.0.9"
+version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "73b4b750c782965c211b42f022f59af1fbceabdd026623714f104152f1ec149f"
+checksum = "f3f6f92acf49d1b98f7a81226834412ada05458b7364277387724a237f062695"
 
 [[package]]
 name = "sct"
@@ -909,27 +879,27 @@ dependencies = [
 
 [[package]]
 name = "semver"
-version = "1.0.7"
+version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d65bd28f48be7196d222d95b9243287f48d27aca604e08497513019ff0502cc4"
+checksum = "a41d061efea015927ac527063765e73601444cdc344ba855bc7bd44578b25e1c"
 dependencies = [
  "serde",
 ]
 
 [[package]]
 name = "serde"
-version = "1.0.136"
+version = "1.0.137"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789"
+checksum = "61ea8d54c77f8315140a05f4c7237403bf38b72704d031543aa1d16abbf517d1"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.136"
+version = "1.0.137"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08597e7152fcd306f41838ed3e37be9eaeed2b61c42e2117266a554fab4662f9"
+checksum = "1f26faba0c3959972377d3b2d306ee9f71faee9714294e41bb777f83f88578be"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -938,9 +908,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.79"
+version = "1.0.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e8d9fa5c3b304765ce1fd9c4c8a3de2c8db365a5b91be52f186efc675681d95"
+checksum = "9b7ce2b32a1aed03c558dc61a5cd328f15aff2dbc17daad8fb8af04d2100e15c"
 dependencies = [
  "itoa",
  "ryu",
@@ -961,11 +931,10 @@ dependencies = [
 
 [[package]]
 name = "serde_with"
-version = "1.12.1"
+version = "1.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "946fa04a8ac43ff78a1f4b811990afb9ddbdf5890b46d6dda0ba1998230138b7"
+checksum = "678b5a069e50bf00ecd22d0cd8ddf7c236f68581b03db652061ed5eb13a312ff"
 dependencies = [
- "rustversion",
  "serde",
  "serde_with_macros",
 ]
@@ -1023,13 +992,13 @@ checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "syn"
-version = "1.0.91"
+version = "1.0.96"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b683b2b825c8eef438b77c36a06dc262294da3d5a5813fac20da149241dcd44d"
+checksum = "0748dd251e24453cb8717f0354206b91557e4ec8703673a4b30208f2abaf1ebf"
 dependencies = [
  "proc-macro2",
  "quote",
- "unicode-xid",
+ "unicode-ident",
 ]
 
 [[package]]
@@ -1099,9 +1068,9 @@ dependencies = [
 
 [[package]]
 name = "tinyvec"
-version = "1.5.1"
+version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2c1c1d5a42b6245520c249549ec267180beaffcc0615401ac8e31853d4b6d8d2"
+checksum = "87cc5ceb3875bb20c2890005a4e226a4651264a5c75edb2421b52861a0a0cb50"
 dependencies = [
  "tinyvec_macros",
 ]
@@ -1114,15 +1083,16 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tokio"
-version = "1.17.0"
+version = "1.19.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2af73ac49756f3f7c01172e34a23e5d0216f6c32333757c2c61feb2bbff5a5ee"
+checksum = "c51a52ed6686dd62c320f9b89299e9dfb46f730c7a48e635c19f21d116cb1439"
 dependencies = [
  "bytes",
  "libc",
  "memchr",
  "mio",
  "num_cpus",
+ "once_cell",
  "pin-project-lite",
  "socket2",
  "winapi",
@@ -1130,9 +1100,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-stream"
-version = "0.1.8"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50145484efff8818b5ccd256697f36863f587da82cf8b409c53adf1e840798e3"
+checksum = "df54d54117d6fdc4e4fea40fe1e4e566b3505700e148a6827e59b34b0d2600d9"
 dependencies = [
  "futures-core",
  "pin-project-lite",
@@ -1141,9 +1111,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-util"
-version = "0.7.1"
+version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0edfdeb067411dba2044da6d1cb2df793dd35add7888d73c16e3381ded401764"
+checksum = "cc463cd8deddc3770d20f9852143d50bf6094e640b485cb2e189a2099085ff45"
 dependencies = [
  "bytes",
  "futures-core",
@@ -1155,9 +1125,9 @@ dependencies = [
 
 [[package]]
 name = "toml"
-version = "0.5.8"
+version = "0.5.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a31142970826733df8241ef35dc040ef98c679ab14d7c3e54d827099b3acecaa"
+checksum = "8d82e1a7758622a465f8cee077614c73484dac5b836c02ff6a40d5d1010324d7"
 dependencies = [
  "serde",
 ]
@@ -1170,34 +1140,22 @@ checksum = "360dfd1d6d30e05fda32ace2c8c70e9c0a9da713275777f5a4dbb8a1893930c6"
 
 [[package]]
 name = "tracing"
-version = "0.1.33"
+version = "0.1.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "80b9fa4360528139bc96100c160b7ae879f5567f49f1782b0b02035b0358ebf3"
+checksum = "a400e31aa60b9d44a52a8ee0343b5b18566b03a8321e0d321f695cf56e940160"
 dependencies = [
  "cfg-if",
  "pin-project-lite",
- "tracing-attributes",
  "tracing-core",
 ]
 
-[[package]]
-name = "tracing-attributes"
-version = "0.1.20"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e65ce065b4b5c53e73bb28912318cb8c9e9ad3921f1d669eb0e68b4c8143a2b"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "tracing-core"
-version = "0.1.24"
+version = "0.1.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90442985ee2f57c9e1b548ee72ae842f4a9a20e3f417cc38dbc5dc684d9bb4ee"
+checksum = "7709595b8878a4965ce5e87ebf880a7d39c9afc6837721b21a5a816a8117d921"
 dependencies = [
- "lazy_static",
+ "once_cell",
 ]
 
 [[package]]
@@ -1214,9 +1172,15 @@ checksum = "dcf81ac59edc17cc8697ff311e8f5ef2d99fcbd9817b34cec66f90b6c3dfd987"
 
 [[package]]
 name = "unicode-bidi"
-version = "0.3.7"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a01404663e3db436ed2746d9fefef640d868edae3cceb81c3b8d5732fda678f"
+checksum = "099b7128301d285f79ddd55b9a83d5e6b9e97c92e0ea0daebee7263e932de992"
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5bd2fe26506023ed7b5e1e315add59d6f584c621d037f9368fea9cfb988f368c"
 
 [[package]]
 name = "unicode-normalization"
@@ -1227,12 +1191,6 @@ dependencies = [
  "tinyvec",
 ]
 
-[[package]]
-name = "unicode-xid"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
-
 [[package]]
 name = "untrusted"
 version = "0.7.1"
@@ -1298,9 +1256,9 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.80"
+version = "0.2.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "27370197c907c55e3f1a9fbe26f44e937fe6451368324e009cba39e139dc08ad"
+checksum = "7c53b543413a17a202f4be280a7e5c62a1c69345f5de525ee64f8cfdbc954994"
 dependencies = [
  "cfg-if",
  "wasm-bindgen-macro",
@@ -1308,9 +1266,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.80"
+version = "0.2.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "53e04185bfa3a779273da532f5025e33398409573f348985af9a1cbf3774d3f4"
+checksum = "5491a68ab4500fa6b4d726bd67408630c3dbe9c4fe7bda16d5c82a1fd8c7340a"
 dependencies = [
  "bumpalo",
  "lazy_static",
@@ -1323,9 +1281,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.80"
+version = "0.2.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "17cae7ff784d7e83a2fe7611cfe766ecf034111b49deb850a3dc7699c08251f5"
+checksum = "c441e177922bc58f1e12c022624b6216378e5febc2f0533e41ba443d505b80aa"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -1333,9 +1291,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.80"
+version = "0.2.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99ec0dc7a4756fffc231aab1b9f2f578d23cd391390ab27f952ae0c9b3ece20b"
+checksum = "7d94ac45fcf608c1f45ef53e748d35660f168490c10b23704c7779ab8f5c3048"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1346,15 +1304,15 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.80"
+version = "0.2.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d554b7f530dee5964d9a9468d95c1f8b8acae4f282807e7d27d4b03099a46744"
+checksum = "6a89911bd99e5f3659ec4acf9c4d93b0a90fe4a2a11f15328472058edc5261be"
 
 [[package]]
 name = "web-sys"
-version = "0.3.57"
+version = "0.3.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b17e741662c70c8bd24ac5c5b18de314a2c26c32bf8346ee1e6f53de919c283"
+checksum = "2fed94beee57daf8dd7d51f2b15dc2bcde92d7a72304cdf662a4371008b71b90"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -1421,11 +1379,54 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
+[[package]]
+name = "windows-sys"
+version = "0.36.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ea04155a16a59f9eab786fe12a4a450e75cdb175f9e0d80da1e17db09f55b8d2"
+dependencies = [
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.36.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9bb8c3fd39ade2d67e9874ac4f3db21f0d710bee00fe7cab16949ec184eeaa47"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.36.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "180e6ccf01daf4c426b846dfc66db1fc518f074baa793aa7d9b9aaeffad6a3b6"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.36.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2e7917148b2812d1eeafaeb22a97e4813dfa60a3f8f78ebe204bcc88f12f024"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.36.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4dcd171b8776c41b97521e5da127a2d86ad280114807d0b2ab1e462bc764d9e1"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.36.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c811ca4a8c853ef420abd8592ba53ddbbac90410fab6903b3e79972a631f7680"
+
 [[package]]
 name = "xattr"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "244c3741f4240ef46274860397c7c74e50eb23624996930e484c16679633a54c"
+checksum = "6d1526bbe5aaeb5eb06885f4d987bcdfa5e23187055de9b83fe00156a821fabc"
 dependencies = [
  "libc",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 80ef338..e94bc41 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,7 +4,7 @@ name = "procfile-buildpack"
 version = "0.0.0"
 publish = false
 edition = "2021"
-rust-version = "1.60"
+rust-version = "1.61"
 
 [dependencies]
 indoc = "1.0.6"
@@ -16,5 +16,3 @@ thiserror = "1.0.31"
 
 [dev-dependencies]
 libcnb-test = "0.3.1"
-tempfile = "3.3.0"
-ureq = "2.4.0"
diff --git a/README.md b/README.md
index 253cece..b79e3a9 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 This is a [Cloud Native Buildpack](https://buildpacks.io/) that replicates the behavior of
 `Procfile` in [Heroku Buildpacks](https://devcenter.heroku.com/articles/buildpacks).
 
-It is written in Rust using the Cloud Native Buildpack framework [libcnb.rs](https://github.com/Malax/libcnb.rs).
+It is written in Rust using the Cloud Native Buildpack framework [libcnb.rs](https://github.com/heroku/libcnb.rs).
 
 ## Deployment
 
@@ -30,7 +30,7 @@ version of the buildpack. A detailed procedure is available [here](github.com/he
 
 ### Prerequisites
 
-See [Development Environment Setup](https://github.com/Malax/libcnb.rs#development-environment-setup).
+See [Development Environment Setup](https://github.com/heroku/libcnb.rs#development-environment-setup).
 
 ### Test
 
@@ -56,14 +56,14 @@ $ cargo test -- --include-ignored
 
 ```
 $ cargo libcnb package \
-&& pack build procfile_example_app --builder heroku/builder:22 --buildpack target/buildpack/debug/heroku_procfile --path tests/fixtures/app_with_procfile --verbose \
+&& pack build procfile_example_app --builder heroku/builder:22 --buildpack target/buildpack/debug/heroku_procfile --path tests/fixtures/web_and_worker_procfile --verbose \
 && docker run -it --rm --entrypoint worker procfile_example_app
 ```
 
 ```
 $ pack inspect procfile_example_app | grep -A10 Processes
 Processes:
-  TYPE                 SHELL        COMMAND              ARGS
-  web (default)        bash         node index.js
-  worker               bash         while true; do echo 'lol'; sleep 2; done
+  TYPE                 SHELL        COMMAND                                   ARGS        WORK DIR
+  web (default)        bash         echo 'this is the web process!'                       /workspace
+  worker               bash         echo 'this is the worker process!'                    /workspace
 ```
diff --git a/src/main.rs b/src/main.rs
index 6cc381f..ccc8ae0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,9 +23,6 @@ use std::path::Path;
 #[cfg(test)]
 use libcnb_test as _;
 
-#[cfg(test)]
-use ureq as _;
-
 struct ProcfileBuildpack;
 
 impl Buildpack for ProcfileBuildpack {
@@ -97,21 +94,15 @@ mod tests {
 
     #[test]
     fn test_valid_detect() {
-        let tmp_dir = tempfile::tempdir().unwrap();
-        let procfile = tmp_dir.path().join("Procfile");
-        std::fs::write(
-            procfile,
-            "julie_andrews: supercalifragilisticexpialidocious",
-        )
-        .unwrap();
-
-        assert!(dir_has_procfile(tmp_dir));
+        let app_dir =
+            Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures/web_and_worker_procfile");
+        assert!(dir_has_procfile(app_dir));
     }
 
     #[test]
     fn test_missing_procfile_detect() {
-        let tmp_dir = tempfile::tempdir().unwrap();
-        assert!(!dir_has_procfile(tmp_dir));
+        let app_dir = Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures/missing_procfile");
+        assert!(!dir_has_procfile(app_dir));
     }
 
     #[test]
diff --git a/tests/fixtures/app_with_procfile/Procfile b/tests/fixtures/app_with_procfile/Procfile
deleted file mode 100644
index 1fa3a06..0000000
--- a/tests/fixtures/app_with_procfile/Procfile
+++ /dev/null
@@ -1,2 +0,0 @@
-web: socat -v -T0.05 tcp-l:8080,reuseaddr,fork system:"echo 'HTTP/1.1 200 OK'; echo 'Connection: close'; echo; cat"
-worker: while true; do echo 'lol'; sleep 2; done
diff --git a/tests/fixtures/app_with_empty_procfile/Procfile b/tests/fixtures/empty_procfile/Procfile
similarity index 100%
rename from tests/fixtures/app_with_empty_procfile/Procfile
rename to tests/fixtures/empty_procfile/Procfile
diff --git a/tests/fixtures/app_without_procfile/.gitkeep b/tests/fixtures/missing_procfile/.gitkeep
similarity index 100%
rename from tests/fixtures/app_without_procfile/.gitkeep
rename to tests/fixtures/missing_procfile/.gitkeep
diff --git a/tests/fixtures/multiple_non_web_procfile/Procfile b/tests/fixtures/multiple_non_web_procfile/Procfile
new file mode 100644
index 0000000..890c80d
--- /dev/null
+++ b/tests/fixtures/multiple_non_web_procfile/Procfile
@@ -0,0 +1,2 @@
+worker: echo 'this is the worker process!'
+console: echo 'this is the console process!'
diff --git a/tests/fixtures/not_yaml_procfile/Procfile b/tests/fixtures/not_yaml_procfile/Procfile
new file mode 100644
index 0000000..f346d4a
--- /dev/null
+++ b/tests/fixtures/not_yaml_procfile/Procfile
@@ -0,0 +1,7 @@
+# Whilst `Procfile`s seem like they could be parsed as though they were a YAML file,
+# this is not the case - for example the below is a valid Procfile, but parsing as
+# YAML would fail with something like
+# `Error : incomplete explicit mapping pair`
+# There is also some leading/trailing whitespace thrown in to confirm we handle that too.
+
+   web: echo foo: bar   
diff --git a/tests/fixtures/web_and_worker_procfile/Procfile b/tests/fixtures/web_and_worker_procfile/Procfile
new file mode 100644
index 0000000..ef08892
--- /dev/null
+++ b/tests/fixtures/web_and_worker_procfile/Procfile
@@ -0,0 +1,2 @@
+web: echo 'this is the web process!'
+worker: echo 'this is the worker process!'
diff --git a/tests/fixtures/worker_only_procfile/Procfile b/tests/fixtures/worker_only_procfile/Procfile
new file mode 100644
index 0000000..1717807
--- /dev/null
+++ b/tests/fixtures/worker_only_procfile/Procfile
@@ -0,0 +1 @@
+worker: echo 'this is the worker process!'
diff --git a/tests/integration_test.rs b/tests/integration_test.rs
index a1fb702..c560354 100644
--- a/tests/integration_test.rs
+++ b/tests/integration_test.rs
@@ -6,47 +6,161 @@
 // Enable Clippy lints that are disabled by default.
 #![warn(clippy::pedantic)]
 
+use indoc::indoc;
 use libcnb_test::assert_contains;
-use libcnb_test::{BuildpackReference, IntegrationTest};
-use std::io;
-use std::thread;
-use std::time::Duration;
+use libcnb_test::IntegrationTest;
 
 #[test]
-#[ignore]
-fn test() {
-    IntegrationTest::new("heroku/builder:22", "tests/fixtures/app_with_procfile")
-        .buildpacks(vec![BuildpackReference::Crate])
-        .run_test(|context| {
-            assert_contains!(context.pack_stdout, "[Discovering process types]");
+#[ignore = "integration test"]
+fn test_web_and_worker_procfile() {
+    IntegrationTest::new(
+        "heroku/builder:22",
+        "tests/fixtures/web_and_worker_procfile",
+    )
+    .run_test(|context| {
+        assert_contains!(
+            context.pack_stdout,
+            indoc! {"
+                [Discovering process types]
+                Procfile declares types -> web, worker
+            "}
+        );
+
+        // When there is a web process type, it should be made the default even if there
+        // are multiple process types declared.
+        assert_contains!(context.pack_stdout, "Setting default process type 'web'");
+        context
+            .prepare_container()
+            .start_with_default_process(|container| {
+                let log_output = container.logs_wait();
+                assert_eq!(log_output.stdout, "this is the web process!\n");
+            });
+
+        context
+            .prepare_container()
+            .start_with_process(String::from("worker"), |container| {
+                let log_output = container.logs_wait();
+                assert_eq!(log_output.stdout, "this is the worker process!\n");
+            });
+    });
+}
+
+#[test]
+#[ignore = "integration test"]
+fn test_worker_only_procfile() {
+    IntegrationTest::new("heroku/builder:22", "tests/fixtures/worker_only_procfile").run_test(
+        |context| {
             assert_contains!(
                 context.pack_stdout,
-                "Procfile declares types -> web, worker"
+                indoc! {"
+                    [Discovering process types]
+                    Procfile declares types -> worker
+                "}
             );
-            assert_contains!(context.pack_stdout, "Setting default process type 'web'");
 
+            // When there is only one process type, it should be made the default process
+            // type even when it doesn't have the name "web".
+            assert_contains!(context.pack_stdout, "Setting default process type 'worker'");
+            context
+                .prepare_container()
+                .start_with_default_process(|container| {
+                    let log_output = container.logs_wait();
+                    assert_eq!(log_output.stdout, "this is the worker process!\n");
+                });
+        },
+    );
+}
+
+#[test]
+#[ignore = "integration test"]
+fn test_multiple_non_web_procfile() {
+    IntegrationTest::new(
+        "heroku/builder:22",
+        "tests/fixtures/multiple_non_web_procfile",
+    )
+    .run_test(|context| {
+        assert_contains!(
+            context.pack_stdout,
+            indoc! {"
+                [Discovering process types]
+                Procfile declares types -> worker, console
+            "}
+        );
+
+        // When there are multiple process types, and none of them has name "web",
+        // then none of them should be set as the default process type.
+        assert_contains!(context.pack_stdout, "no default process type");
+        context
+            .prepare_container()
+            .start_with_default_process(|container| {
+                let log_output = container.logs_wait();
+                assert_contains!(
+                    log_output.stdout,
+                    "when there is no default process a command is required"
+                );
+            });
+
+        context
+            .prepare_container()
+            .start_with_process(String::from("worker"), |container| {
+                let log_output = container.logs_wait();
+                assert_eq!(log_output.stdout, "this is the worker process!\n");
+            });
+
+        context
+            .prepare_container()
+            .start_with_process(String::from("console"), |container| {
+                let log_output = container.logs_wait();
+                assert_eq!(log_output.stdout, "this is the console process!\n");
+            });
+    });
+}
+
+#[test]
+#[ignore = "integration test"]
+// Tests a Procfile that happens to not be valid YAML, but is still valid according
+// to the supported Procfile syntax.
+fn test_not_yaml_procfile() {
+    IntegrationTest::new("heroku/builder:22", "tests/fixtures/not_yaml_procfile").run_test(
+        |context| {
+            assert_contains!(
+                context.pack_stdout,
+                indoc! {"
+                    [Discovering process types]
+                    Procfile declares types -> web
+                "}
+            );
+            assert_contains!(context.pack_stdout, "Setting default process type 'web'");
             context
                 .prepare_container()
-                .expose_port(8080)
                 .start_with_default_process(|container| {
-                    thread::sleep(Duration::from_secs(1));
-                    let result = call_test_fixture_service(
-                        container.address_for_port(8080).unwrap(),
-                        "Aeluon",
-                    )
-                    .unwrap();
-
-                    assert_contains!(result, "payload=Aeluon");
+                    let log_output = container.logs_wait();
+                    assert_eq!(log_output.stdout, "foo: bar\n");
                 });
-        });
+        },
+    );
 }
 
-fn call_test_fixture_service(addr: std::net::SocketAddr, payload: &str) -> io::Result<String> {
-    let req = ureq::get(&format!(
-        "http://{}:{}/?payload={}",
-        addr.ip(),
-        addr.port(),
-        payload
-    ));
-    req.call().unwrap().into_string()
+#[test]
+#[ignore = "integration test"]
+fn test_empty_procfile() {
+    IntegrationTest::new("heroku/builder:22", "tests/fixtures/empty_procfile").run_test(
+        |context| {
+            assert_contains!(
+                context.pack_stdout,
+                indoc! {"
+                    [Discovering process types]
+                    Procfile declares types -> (none)
+                "}
+            );
+            assert_contains!(context.pack_stdout, "no default process type");
+        },
+    );
+}
+
+#[test]
+#[ignore = "integration test"]
+#[should_panic(expected = "ERROR: No buildpack groups passed detection.")]
+fn test_missing_procfile() {
+    IntegrationTest::new("heroku/builder:22", "tests/fixtures/missing_procfile").run_test(|_| {});
 }