Add support for Laravel 9

Author: ivanvermeyen

composer.json

@@ -21,7 +21,7 @@
         "php": "^7.0|^8.0"
     },
     "require-dev": {
-        "illuminate/support": "^5.5|^6.0|^7.0|^8.0",
+        "illuminate/support": "^5.5|^6.0|^7.0|^8.0|^9.0",
         "mockery/mockery": "^1.3.3",
         "phpunit/phpunit": "^6.0|^7.0|^8.0|^9.0"
     },
@@ -52,4 +52,4 @@
     },
     "minimum-stability": "stable",
     "prefer-stable": true
-}
+}