Write basic tests

[WillNilges]

Tests make the world go round :)

[andybaumgar]

Started brainstorming in this Slack thread.

[WillNilges]

#27

[WillNilges]

Our README instructions are probably broken.

I don't think this will work in current state. We would need to add some config to pyproject.toml to tell pytest where to look for tests. Though I think we probably actually want to just use Django's wizardry to make this more pleasant and run python manage.py test instead per the recommendation in the docs: https://docs.djangoproject.com/en/4.2/topics/testing/overview/

[WillNilges]

manage.py test

[andybaumgar]

Should use standard Django testing method: https://docs.djangoproject.com/en/4.2/topics/testing/overview/

[Andrew-Dickinson]

Acceptance criteria:

• Have non-zero number of tests
• Line coverage at 50% or higher
• Readme instructions
  • for running existing tests
  • & how to add a new test

Out of scope:

• Anything CI related. Okay to require devs to run tests manually. See Add CI #9

[WillNilges]

#70