Created wait_for_db command to ensure django app connects to the db a…

…fter it is ready. This will ensure that app is consistently able to run without erroring out for trying to connect to the db too early.

.github/workflows/checks.yml

@@ -16,6 +16,6 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
       - name: Testing
-        run: docker-compose run --rm app sh -c "python manage.py test"
+        run: docker-compose run --rm app sh -c "python manage.py wait_for_db && python manage.py test"
       - name: Linting
         run: docker-compose run --rm app sh -c "flake8"