chore: PHP 8 support (#920)

# Conflicts:
#	composer.json

Author: C0kkie

composer.json

@@ -24,12 +24,12 @@
         }
     ],
     "require": {
-        "php": "^7.2.5",
+        "php": "^7.2.5|^8.0",
         "illuminate/support": "^7.0",
         "laracasts/flash": "^3.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^8.5",
+        "phpunit/phpunit": "^8.5|^9.3.3",
         "mockery/mockery": "^1.3.1"
     },
     "autoload": {