Update tests workflow for GitHub Actions

Author: divineniiquaye

.github/workflows/tests.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Setup PHP, with composer and extensions
         uses: shivammathur/setup-php@v2
         with:
-          php-version: ${{ matrix.php-versions }}
+          php-version: ${{ matrix.php }}
           extensions: mbstring, curl
           coverage: xdebug
           tools: composer:v2