Merge pull request #10 from Codeception/php8

PHP8 compatibility

Author: Naktibalda

.github/workflows/main.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        php: [5.6, 7.0, 7.1, 7.2, 7.3, 7.4]
+        php: [5.6, 7.0, 7.1, 7.2, 7.3, 7.4, 8.0]
 
     steps:
     - name: Checkout code

Robofile.php

@@ -19,13 +19,10 @@
     ],
     "minimum-stability": "RC",
     "require": {
-        "php": ">=5.6.0 <8.0",
+        "php": ">=5.6.0 <9.0",
         "codeception/lib-asserts": "^1.13.1",
         "codeception/codeception": "*@dev"
     },
-    "require-dev": {
-        "codeception/util-robohelpers": "dev-master"
-    },
     "conflict": {
         "codeception/codeception": "<4.0"
     },