Add laravel 9 support (#13)

* remove conflicting illuminate/support

* update required illuminate/http version

Author: samuelhowell

composer.json

@@ -10,8 +10,7 @@
     "request"
   ],
   "require": {
-    "illuminate/http": "^5.0|^6.0|^7.0|^8.0",
-    "illuminate/support": "^5.0|^6.0|^7.0|^8.0"
+    "illuminate/http": "^5.0|^6.0|^7.0|^8.0|^v9.0"
   },
   "require-dev": {
     "phpunit/phpunit": "~5.4.0"