Update phpstan & easy coding standard (#366)

Author: marmichalski

composer.json

@@ -24,9 +24,9 @@
     },
     "require-dev": {
         "phpbench/phpbench": "^0.14.0",
-        "phpstan/phpstan-phpunit": "^0.10",
-        "phpstan/phpstan-shim": "^0.10",
-        "phpstan/phpstan-strict-rules": "^0.10",
+        "phpstan/phpstan-phpunit": "^0.11",
+        "phpstan/phpstan-shim": "^0.11",
+        "phpstan/phpstan-strict-rules": "^0.11",
         "phpunit/phpunit": "^7.0.0",
         "symplify/coding-standard": "^5.1",
         "symplify/easy-coding-standard": "^5.1"