CI - Add tests for PHP 8.0 in GH actions

Author: landrok

.github/workflows/php.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-versions: ['7.2', '7.3', '7.4']
+        php-versions: ['7.2', '7.3', '7.4', '8.0']
 
     steps:
     - name: Checkout