Updated php version constraint to allow 8.0

Author: bjornvoesten

composer.json

@@ -14,7 +14,7 @@
     "test": "./vendor/bin/phpunit ./tests"
   },
   "require": {
-    "php": "^7.4",
+    "php": "^7.4|^8.0",
     "illuminate/collections": "^6.0|^7.0|^8.0"
   },
   "require-dev": {