supported php8

Author: polidog

.github/workflows/test.yaml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       max-parallel: 5
       matrix:
-        php-versions: [ '7.0', '7.1', '7.2', '7.3', '7.4' ]
+        php-versions: [ '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2' ]
 
     steps:
       - uses: actions/checkout@v1
@@ -17,4 +17,4 @@ jobs:
           composer install
       - name: phpunit
         run: |
-          composer test
+          composer test