Support PHP 8

Author: Naktibalda

composer.json

@@ -22,7 +22,7 @@
     "minimum-stability": "RC",
 
     "require": {
-        "php": ">=5.6.0 <8.0",
+        "php": ">=5.6.0 <9.0",
         "ext-dom": "*",
         "codeception/phpunit-wrapper": ">6.0.15 <6.1.0 | ^6.6.1 | ^7.7.1 | ^8.0.3 | ^9.0"
     },