Set up unit testing

[ankitr]

See ProjectCopilot/volunteer#2

[gmittal]

Probably not needed for the concierge frontend?

[ankitr]

We should write tests for at least the question logic, esp. as we're have a pretty involved data structure (and just for good habits). Also, it will help to have testing infrastructure set up in case concierge grows in scope in the future.

[gmittal]

Alright. Fair enough.