Exclude migrations from coverage reports

.github/workflows/django.yml

@@ -48,7 +48,7 @@ jobs:
         DB_PASSWORD: ${{ matrix.db_password }}
         SECRET_KEY: dummy-key
       run: |
-        coverage run --omit=*/tests/* --source=hc manage.py test
+        coverage run --omit=*/tests/*,*/migrations/* --source=hc manage.py test
     - name: Coveralls
       if: matrix.db == 'postgres' && matrix.python-version == '3.8'
       run: coveralls --service=github