[MCC-140730] Feature/delete

merge after #13 

PR Adds a delete spec, cleans up the delete to return a true no body 204.  Refactors all that .hale_json stuff to use a helper hale_url_for.

```
Finished in 37.88 seconds (files took 0.51877 seconds to load)
14 examples, 0 failures, 2 pending

Randomized with seed 43121
```
addressed in #15