Allow PHP 8 support in composer

Helps avoid this issue with the composer when running on PHP 8 environments. Pulled the commit off the suggestions from this issue JacobBennett#48

composer.json

@@ -17,7 +17,7 @@
         }
     ],
     "require": {
-        "php" : "^7.2",
+        "php" : "^7.0|^8.0",
         "illuminate/support": "~6.0|~7.0|~8.0",
         "illuminate/http": "~6.0|~7.0|~8.0",
         "symfony/dom-crawler": "^2.7|^3.0|^4.0|^5.0",