Make package compatible with php8 (fedeisas#146)

* Update composer.json

php 8

* Update composer.json

Author: sietzekeuning

composer.json

@@ -14,7 +14,7 @@
         }
     ],
     "require": {
-        "php": "^7.2.5",
+        "php": "^7.2|^8.0",
         "ext-dom": "*",
         "illuminate/mail": "^7.4 || ^8.0",
         "illuminate/support": "^7.4 || ^8.0",