Test on PHP 8.0

Author: oschwald

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [ubuntu-latest]
-        php-versions: ['7.2', '7.3', '7.4']
+        php-versions: ['7.2', '7.3', '7.4', '8.0']
     name: "PHP ${{ matrix.php-versions }} test on ${{ matrix.operating-system }}"
     steps:
       - name: Setup PHP