Use newer Github actions (#1329)

Author: X-Coder264

.github/workflows/tests.yml

@@ -20,10 +20,10 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
 
       - name: Setup PHP
-        uses: shivammathur/setup-php@v1
+        uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
           extensions: dom, curl, libxml, mbstring, zip, pcntl, pdo, sqlite, pdo_sqlite, bcmath, soap, intl, gd, exif, iconv, imagick