Many more tests, `jawn_type` attribute added to Spark and Idea

Added routes testing, and improved testing of Spark model.

In response to Sam's recent commit, I added a `jawn_type` attribute which is returned as a json attribute of either "idea" or "spark" based on the object type. This should allow the android side to differentiate between sparks and ideas when using `/api/v1/jawns.json` to fetch all recent jawns.