[Bug] SQLAlchemy 1.4.x doesn't work

With 1.3: https://github.com/codeforboston/police-data-trust/actions/runs/1006498785

With 1.4: https://github.com/codeforboston/police-data-trust/actions/runs/1006417486

The error message received in 1.4:

`AttributeError: Mock object has no attribute '_contextual_connect'`