Unit tests for existing code

[martian-a]

Before we refactor our existing code we should have unit tests in place so that we can use them for regression testing.

[cbetta]

👍 though I'd focus mainly on integration tests than on model tests for now just to be able to cover more ground in less time

[martian-a]

Branch created for unit tests: 133_unit_tests.

[martian-a]

i think our code base is still small enough that it would be worth at least attempting to get the unit tests in place. Hopefully they'll make it easier to pin down exactly what went wrong if/when an integration test fails. But you're welcome to add in integration tests too (new ticket?).