Add test workflow

Author: abnegate

.github/workflows/tests.yml

@@ -0,0 +1,21 @@
+name: "Tests"
+
+on: [pull_request]
+jobs:
+  test:
+    name: Tests
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v3
+      with:
+        fetch-depth: 2
+
+    - run: git checkout HEAD^2
+
+    - name: Run Tests
+      run: |
+        docker compose up -d
+        sleep 10
+        docker compose exec -T web vendor/bin/phpunit --configuration phpunit.xml