Update PHPStan

Author: ondrejmirtes

composer.json

@@ -13,8 +13,8 @@
         "mockery/mockery": "^1.2.4",
         "phing/phing": "^2.16.3",
         "php-parallel-lint/php-parallel-lint": "^1.2",
-        "phpstan/phpstan-phpunit": "^0.12",
-        "phpstan/phpstan-strict-rules": "^0.12",
+        "phpstan/phpstan-phpunit": "^0.12.16",
+        "phpstan/phpstan-strict-rules": "^0.12.5",
         "phpunit/phpunit": "^7.5.20"
     },
     "config": {