Update wordpress.yml

.github/workflows/wordpress.yml

@@ -18,10 +18,19 @@ jobs:
       uses: shivammathur/setup-php@v2
       with:
         php-version: '7.4'
+    - name: Cache Composer dependencies
+      uses: actions/cache@v2
+      with:
+        path: ~/.composer/cache
+        key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-composer-
     - name: Install dependencies
       run: cd wordpress-app && composer install
+    - name: Install PHPUnit
+      run: composer require --dev phpunit/phpunit
     - name: Test
-      run: phpunit
+      run: vendor/bin/phpunit
     - name: Dockerhub Login
       uses: docker/login-action@v2
       with: