Fix ci

Author: s1lver

.github/workflows/main.yml

@@ -20,7 +20,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: [ 5.6, 7.0, 7.1, 7.2, 7.3, 7.4, 8.0 ]
+        php: [ '5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0' ]
     steps:
       - name: Checkout
         uses: actions/checkout@v2