Added github workflow to run pytest

.github/workflows/tests.yml

@@ -0,0 +1,18 @@
+name: Tests
+on: [pull_request]
+
+jobs:
+  run_tests:
+    runs-on: ubuntu-latest
+    steps:
+      # https://github.com/actions/checkout
+      - uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and start containers
+        run: docker-compose up -d --build meldingen-core
+
+      - name: Test migrations
+        run: docker-compose exec -T meldingen-core pytest -v