code hygiene

[jhellerstein]

1. I'm concerned about fallback logic hiding bugs in our code. Let's do a TDD-based sweep of all fallback logic. For each fallback we consider removing, we should replace it with an error and have a regression test that exercises that code to make sure it doesn't run into the error. If the test is failing we should decide how to deal with the bug.

2. Let's remove the use of any from Hydroscope, and make sure we have proper types throughout.