Add Support for Laravel 8

Author: cyrillkalita

composer.json

@@ -19,11 +19,11 @@
     ],
     "require": {
         "php": "^7.2",
-        "illuminate/support": "~5.8.0|^6.0|^7.0",
+        "illuminate/support": "~5.8.0|^6.0|^7.0|^8.0",
         "spatie/laravel-webhook-client": "^2.0"
     },
     "require-dev": {
-        "orchestra/testbench": "~3.8.0|^4.0|^5.0",
+        "orchestra/testbench": "~3.8.0|^4.0|^5.0|^6.0",
         "phpunit/phpunit": "^8.2|^9.0"
     },
     "autoload": {