Add php 8.x support.

Author: HyanCat

composer.json

@@ -29,7 +29,7 @@
         }
     ],
     "require": {
-        "php": "^7.0",
+        "php": "^7.0|^8.0",
         "ext-json": "*",
         "guzzlehttp/guzzle": "^6.0",
         "illuminate/notifications": "^5.5|^6.0|^7.0|^8.0",