Fix phpstan requirement

The caret operator behaves differently for pre release versions so
there must be both minor versions in the requirement.

Author: sascha-egerer

composer.json

@@ -7,7 +7,7 @@
     "prefer-stable": true,
     "require": {
         "php": "~7.1",
-        "phpstan/phpstan": "^0.10",
+        "phpstan/phpstan": "^0.10 || ^0.11",
         "typo3/cms-core": "^8.7 || ^9.5 || ^10.0",
         "typo3/cms-extbase": "^8.7 || ^9.5 || ^10.0"
     },