Remove warning version

Author: snapshotpl

composer.json

@@ -14,7 +14,7 @@
         "http-interop/http-middleware": "^0.4.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.6 || ^6.1"
+        "phpunit/phpunit": "^5.6.1 || ^6.1"
     },
     "autoload": {
         "psr-4": {