ci: Build and test on Go 1.16, bump minimum to 1.15 (#4024)

* ci: Build and test on Go 1.16

* ci: Drop Go 1.14 support

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ ubuntu-latest, macos-latest, windows-latest ]
-        go: [ '1.14', '1.15' ]
+        go: [ '1.15', '1.16' ]
 
         # Set some variables per OS, usable via ${{ matrix.VAR }}
         # CADDY_BIN_PATH: the path to the compiled Caddy binary, for artifact publishing

.github/workflows/cross-build.yml

@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         goos: ['android', 'linux', 'solaris', 'illumos', 'dragonfly', 'freebsd', 'openbsd', 'plan9', 'windows', 'darwin', 'netbsd']
-        go: [ '1.14', '1.15' ]
+        go: [ '1.15', '1.16' ]
     runs-on: ubuntu-latest
     continue-on-error: true
     steps:

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-latest ]
-        go: [ '1.15' ]
+        go: [ '1.16' ]
     runs-on: ${{ matrix.os }}
 
     steps:

README.md

@@ -75,7 +75,7 @@ For other install options, see https://caddyserver.com/docs/download.
 
 Requirements:
 
-- [Go 1.14 or newer](https://golang.org/dl/)
+- [Go 1.15 or newer](https://golang.org/dl/)
 
 ### For development
 

go.mod

@@ -1,6 +1,6 @@
 module github.com/caddyserver/caddy/v2
 
-go 1.14
+go 1.15
 
 require (
 	github.com/Masterminds/sprig/v3 v3.1.0