Review / refactor ENTIRE test suite

[orenyk]

While writing up #1411 it occurred to me that we have a lot of old tests that are probably sub-optimal. Our Travis builds now takes almost 5 minutes, which is really far too long for an app of our complexity and a test suite of our size. I'd like to completely overhaul the test suite, focusing on building a nice test pyramid and avoiding DB hits as much as possible through mocks / stubs.

This is going to be a fairly massive undertaking, so if others are interested in improving their testing skills we can definitely split it up.

[squidgetx]

diff: 13

[orenyk]

hahaha - we should crank it up to 11 😄

[orenyk]

We also really need to start using test doubles, they're so much faster than creating db-backed objects, it's insane (see #1433). We could probably cut our test suite time in half just by correctly using them.

[orenyk]

This might be both useful and painful 😛.