introduce the concept of backfire

The idea here is to have a strategy for moving away from integration tests. When mocking is done via cassette as it is currently designed, we are left with a lot of work to pass the tests each time we change what is being requested from a dependent service to another service. By using "backfire", we can start to slowly and methodically remove HTTP dependencies from our tests, and move towards a unit-test only mindset.

At the end of the day, the data coming over the wire must be allowed to be malleable. We can't code our tests against old data.