Dont lock PHPStan dependency to v0.11, allow ^0.11

It's probably a typo but since PHPStan has upgraded to 0.11.1 I get this error while require the package:

Author: tigitz

composer.json

@@ -11,7 +11,7 @@
     ],
     "require": {
         "php": "^7.1",
-        "phpstan/phpstan": "^0.10 | v0.11",
+        "phpstan/phpstan": "^0.10 | ^0.11",
         "thecodingmachine/safe": "^0.1.11"
     },
     "require-dev": {