diff --git a/Pipfile b/Pipfile
index 6b3c75eb..381b1090 100644
--- a/Pipfile
+++ b/Pipfile
@@ -7,9 +7,9 @@ name = "pypi"
 
 [packages]
 
-cython = "==0.28.1"
+cython = "==0.28.2"
 pydocstyle = "==2.1.1"
-pylint = "==1.8.3"
+pylint = "==1.8.4"
 mypy-lang = "==0.5.0"
 coverage = "==4.5.1"
 pytest = "==3.5.0"
diff --git a/Pipfile.lock b/Pipfile.lock
index 369a2712..aced4283 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -29,10 +29,10 @@
     "default": {
         "astroid": {
             "hashes": [
-                "sha256:b76e5109ff0f386dd229673ca1323d21b1e9bb9c38eaed2cf830882dd7628be2",
-                "sha256:a92c1197dd496ef2470e73e1c296fc02a719907ee07259744e26a13bda9d4862"
+                "sha256:38186e481b65877fd8b1f9acc33e922109e983eb7b6e487bd4c71002134ad331",
+                "sha256:35cfae47aac19c7b407b7095410e895e836f2285ccf1220336afba744cc4c5f2"
             ],
-            "version": "==1.6.2"
+            "version": "==1.6.3"
         },
         "certifi": {
             "hashes": [
@@ -98,38 +98,38 @@
         },
         "cython": {
             "hashes": [
-                "sha256:7cdd5303121024269610236876d9f4beb6a909a1ea5d7bc48e7bbf5d8774a3f2",
-                "sha256:330c95c03e39835976d1410f5fa877b75fcc5c50dc146d4c02377fc719b1f8c9",
-                "sha256:e27e12834ac315c7d67ca697a325d42ff8395e9b82fb62c8665bb583eb0df589",
-                "sha256:d08f5dd2fbf7d1506c9d986a8352b2423170002ddb635b184d2a916d2b5df0d6",
-                "sha256:26196ff8fe00e7c4c5815a310c368edfc1a1c8a3c90ac9220435d1b01e795cf7",
-                "sha256:ea22d79133583b5b0f856dbfda097363228ae0a3d77431deaba90634e5d4853a",
-                "sha256:1a434e7621ca6671ce949893fef94b13a580853ba976e729f68dda5ab270ee8a",
-                "sha256:d2b636c16931663aeb8ffb91cf871a912e66e7200755ce68aa8c502c16eb366f",
-                "sha256:15cbde95cdf6a346c63c0b38b895aa3186d0a49adcaf42b9e19c4cb0473cb921",
-                "sha256:b5c2e31be55bc61d3c758889d06b16d84f4fda944832fbed63c113ec2dbc5f97",
-                "sha256:ea113ff58e96152738e646b8ee77b41d3994735df77bee0a26cd413a67e03c0f",
-                "sha256:4e07e619af85e7c1ec2344ecab558929bb4acbca25f8f170d07dc677e8ee413f",
-                "sha256:32638aefc164404ac70e5f86558cd3aece34df17db16da905abf5e664073bae4",
-                "sha256:996ae959ab2600b8ad4c80981afc32e89b42d0abe3234c48e960e40180459cb2",
-                "sha256:0a44c3645a84724d4f7f7c1126f3807cad14271f210bb1a9a15bfd330c8d20b9",
-                "sha256:2b73b062658511167dde37a51acb80ae6ddea1ffa284ebdbc47a900f21e63c70",
-                "sha256:3fc9b945541cadb5a10316e48b5e73f4b6f635b7d30156f502b66f3766545b23",
-                "sha256:427299c47cfe04d97f9f09ea55570c05898a87b64caf6ddebb529b6f64e5d228",
-                "sha256:5010e048fb9791522fe626bd40137b8a847ba77a6e656bb64d6d7acdc45ece32",
-                "sha256:80856aa45004514a3ff5e102bd18fbd5230d234311de1f83d4e5b97ef42f6c93",
-                "sha256:1da199a5be7c486ee89b4a8bda7f00f9fd98b800d9af3a1fe3fc63e68dadea85",
-                "sha256:2b9aa64473fefbe988e36a30915732a0e2a75ffe0f3e81a70e3f8d367c2e4119",
-                "sha256:e47bbe74d6c87fab2e22f1580aa3e4a8e7482b4265b1fc76685fc49f90e18f99",
-                "sha256:e312dd688b97e9f97199a8e4ba18b65db2747157630761d27193a18761b23fed",
-                "sha256:38b499fa317cf6939e46317457240553b13e974f08ed387523f10af26e269f6c",
-                "sha256:70bc2806fc9e5affcf74c0d4fa12cba57ffb94cdfc28b975692c8df56ea86402",
-                "sha256:3c60caa0075aa1f1c5e10b5352d2e8bb9a18361ce9fca50fa7d4baea67804ade",
-                "sha256:c39b3a042bf5ded7c8336c82b1fa817e1f46a7ef16d41d66b3d3340e7a3b60ed",
-                "sha256:175273eb6a90af364b9b2aea74e3c3eebcde9caec02d617cd8886c0933ec3304",
-                "sha256:152ee5f345012ca3bb7cc71da2d3736ee20f52cd8476e4d49e5e25c5a4102b12"
-            ],
-            "version": "==0.28.1"
+                "sha256:e05d28b5ce1ee5939d83e50344980659688ecaed65c5e10214d817ecf5d1fe6a",
+                "sha256:4cfda677227af41e4502e088ee9875e71922238a207d0c40785a0fb09c703c21",
+                "sha256:0d2ccb812d73e67557fd16e7aa7bc5bac18933c1dfe306133cd0680ccab89f33",
+                "sha256:7656895cdd59d56dd4ed326d1ee9ede727020d4a5d8778a05af2d8e25af4b13d",
+                "sha256:6ba89d56c3ee45716378cda4f0490c3abe1edf79dce8b997f31608b14748a52b",
+                "sha256:4ec60a4086a175a81b9258f810440a6dd2671aa4b419d8248546d85a7de6a93f",
+                "sha256:9a465e7296a4629139be5d2015577f2ae5e08196eb7dc4c407beea130f362dc3",
+                "sha256:96dd674e72281d3feed74fd5adcf0514ba02884f123cdf4fb78567e7be6b1694",
+                "sha256:03db8c1b8120039f72493b95494a595be13b01b6860cfc93e2a651a001847b3b",
+                "sha256:c623d19fcc60ea27882f20cf484218926ddf6f978b958dae1070600a1974f809",
+                "sha256:9eab3696f2cb88167db109d737c787fb9dd34ca414bd1e0c424e307956e02c94",
+                "sha256:67e0359709c8addc3ecb19e1dec6d84d67647e3906da618b953001f6d4480275",
+                "sha256:9a60355edca1cc9006be086e2633e190542aad2bf9e46948792a48b3ae28ed97",
+                "sha256:6ca5436d470584ba6fd399a802c9d0bcf76cf1edb0123725a4de2f0048f9fa07",
+                "sha256:c3ae7d40ebceb0d944dfeeceaf1fbf17e528f5327d97b008a8623ddddd1ecee3",
+                "sha256:cf17af0433218a1e33dc6f3069dd9e7cd0c80fe505972c3acd548e25f67973fd",
+                "sha256:85f7432776870d65639fed00f951a3c05ef1e534bc72a73cd1200d79b9a7d7d0",
+                "sha256:51c7d48ea4cba532d11a6d128ebbc15373013f816e5d1c3a3946650b582a30b8",
+                "sha256:97bf06a89bcf9e8d7633cde89274d42b3b661dc974b58fca066fad762e46b4d8",
+                "sha256:6a93d4ba0461edc7a359241f4ebbaa8f9bc9490b3540a8dd0460bef8c2c706db",
+                "sha256:24f8ea864de733f5a447896cbeec2cac212247e33272539670b9f466f43f23db",
+                "sha256:f5f6694ce668eb7a9b59550bfe4265258809c9b0665c206b26d697df2eef2a8b",
+                "sha256:db40de7d03842d3c4625028a74189ade52b27f8efaeb0d2ca06474f57e0813b2",
+                "sha256:c719a6e86d7c737afcc9729994f76b284d1c512099ee803eff11c2a9e6e33a42",
+                "sha256:4984e097bc9da37862d97c1f66dacf2c80fadaea488d96ba0b5ea9d84dbc7521",
+                "sha256:37e680901e6a4b97ab67717f9b43fc58542cd10a77431efd2d8801d21d5a37d4",
+                "sha256:daf96e0d232605e979995795f62ffd24c5c6ecea4526e4cbb86d80f01da954b2",
+                "sha256:30a8fd029eb932a7b5a74e158316d1d069ccb67a8607aa7b6c4ed19fab7fbd4a",
+                "sha256:deea1ef59445568dd7738fa3913aea7747e4927ff4ae3c10737844b8a5dd3e22",
+                "sha256:634e2f10fc8d026c633cffacb45cd8f4582149fa68e1428124e762dbc566e68a"
+            ],
+            "version": "==0.28.2"
         },
         "docopt": {
             "hashes": [
@@ -195,10 +195,10 @@
         },
         "mypy": {
             "hashes": [
-                "sha256:7247f9948d7cdaae9408a4ee1662a01853c24e668117b4419acf025b05fbe3ce",
-                "sha256:3bd95a1369810f7693366911d85be9f0a0bd994f6cb7162b7a994e5ded90e3d9"
+                "sha256:cdd3ddf96a2cc2e955bcc7b2a16b25e400f132393375b45a2d719c91ac1a8291",
+                "sha256:04bffef22377b3f56f96da2d032e5d0b2e8a9062a127afc008dc4b0e64cede7a"
             ],
-            "version": "==0.580"
+            "version": "==0.590"
         },
         "mypy-lang": {
             "hashes": [
@@ -208,17 +208,17 @@
         },
         "psutil": {
             "hashes": [
-                "sha256:82a06785db8eeb637b349006cc28a92e40cd190fefae9875246d18d0de7ccac8",
-                "sha256:4152ae231709e3e8b80e26b6da20dc965a1a589959c48af1ed024eca6473f60d",
-                "sha256:230eeb3aeb077814f3a2cd036ddb6e0f571960d327298cc914c02385c3e02a63",
-                "sha256:a3286556d4d2f341108db65d8e20d0cd3fcb9a91741cb5eb496832d7daf2a97c",
-                "sha256:94d4e63189f2593960e73acaaf96be235dd8a455fe2bcb37d8ad6f0e87f61556",
-                "sha256:c91eee73eea00df5e62c741b380b7e5b6fdd553891bee5669817a3a38d036f13",
-                "sha256:779ec7e7621758ca11a8d99a1064996454b3570154277cc21342a01148a49c28",
-                "sha256:8a15d773203a1277e57b1d11a7ccdf70804744ef4a9518a87ab8436995c31a4b",
-                "sha256:e2467e9312c2fa191687b89ff4bc2ad8843be4af6fb4dc95a7cc5f7d7a327b18"
+                "sha256:8f208867d41eb3b6de416df098a9a28d08d40b432467d821b8ef5bb589a394ce",
+                "sha256:77b5e310de17085346ef2c4c21b64d5e39616ab4559b8ef6fea9f6f2ab0de66f",
+                "sha256:fec0e59dacbe91db7e063f038301f49da7e9361732fc31d28338ecaa4719520e",
+                "sha256:1268fb6959cd8d761c30e13e79908ae73ba5a69c3c3a5d09a7a27278446f9800",
+                "sha256:7eb2d80ef79d90474a03eead13b32e541d1fdeb47468cf04c881f0a7392ddbc5",
+                "sha256:69f1db4d13f362ce11a6246b20c752c31b87a6fd77452170fd03c26a8a20a4f2",
+                "sha256:6eb59bcfd48eade8889bae67a16e0d8c7b18af0732ba64dead61206fd7cb4e45",
+                "sha256:a4af5d4fcf6022886a30fb3b4fff71ff25f645865a68506680d43a3e634764af",
+                "sha256:5959e33e0fc69742dd22e88bfc7789a1f2e1fc2297794b543119e10cdac8dfb1"
             ],
-            "version": "==5.4.3"
+            "version": "==5.4.4"
         },
         "py": {
             "hashes": [
@@ -237,10 +237,10 @@
         },
         "pylint": {
             "hashes": [
-                "sha256:34ab1a62fbdd48059d082f5a52b7e719a39b757a53ecbf0b2b7169b9c6a2cc28",
-                "sha256:c77311859e0c2d7932095f30d2b1bfdc4b6fe111f534450ba727a52eae330ef2"
+                "sha256:0b7e6b5d9f1d4e0b554b5d948f14ed7969e8cdf9a0120853e6e5af60813b18ab",
+                "sha256:34738a82ab33cbd3bb6cd4cef823dbcabdd2b6b48a4e3a3054a2bbbf0c712be9"
             ],
-            "version": "==1.8.3"
+            "version": "==1.8.4"
         },
         "pytest": {
             "hashes": [
@@ -415,17 +415,10 @@
         },
         "pytz": {
             "hashes": [
-                "sha256:ed6509d9af298b7995d69a440e2822288f2eca1681b8cce37673dbb10091e5fe",
-                "sha256:f93ddcdd6342f94cea379c73cddb5724e0d6d0a1c91c9bdef364dc0368ba4fda",
-                "sha256:61242a9abc626379574a166dc0e96a66cd7c3b27fc10868003fa210be4bff1c9",
-                "sha256:ba18e6a243b3625513d85239b3e49055a2f0318466e0b8a92b8fb8ca7ccdf55f",
-                "sha256:07edfc3d4d2705a20a6e99d97f0c4b61c800b8232dc1c04d87e8554f130148dd",
-                "sha256:3a47ff71597f821cd84a162e71593004286e5be07a340fd462f0d33a760782b5",
-                "sha256:5bd55c744e6feaa4d599a6cbd8228b4f8f9ba96de2c38d56f08e534b3c9edf0d",
-                "sha256:887ab5e5b32e4d0c86efddd3d055c1f363cbaa583beb8da5e22d2fa2f64d51ef",
-                "sha256:410bcd1d6409026fbaa65d9ed33bf6dd8b1e94a499e32168acfc7b332e4095c0"
-            ],
-            "version": "==2018.3"
+                "sha256:65ae0c8101309c45772196b21b74c46b2e5d11b6275c45d251b150d5da334555",
+                "sha256:c06425302f2cf668f1bba7a0a03f3c1d34d4ebeef2c72003da308b3947c7f749"
+            ],
+            "version": "==2018.4"
         },
         "requests": {
             "hashes": [
diff --git a/requirements.txt b/requirements.txt
index dac37af5..7e83469f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,13 +1,13 @@
 # pip
 # wheel
 
-cython==0.28.1
+cython==0.28.2
 
 # key components for improving Python project
 # we will install them on "Testing" section
 # but let's lock version here and use bot to trigger each version update
 pydocstyle==2.1.1
-pylint==1.8.3
+pylint==1.8.4
 # flake8==3.4.1
 mypy-lang==0.5.0
 coverage==4.5.1