End to end test coverage of Terms Controller

See #650, #581
I like these style tests for a couple of reasons:

1. The pattern of using the path to define the endpoint is more intuitive than "pure" unit rests.
2. The tests cover route registry and argument declaration, which is something that's easy to get wrong or forget to add tests for.

I think the performance impact is negligible. If the only argument against is a religious one, then I'm a strong +1 for adopting this pattern across the board.