Remove tests that duplicate Need unit tests.
Don't crash if Need API returns a 422
Add integration test for handling Need API 422s
Add unit test for need not saving
Not displaying specific save errors
Remove unnecessary test data
Make test more readable
Call to_json in the correct place in the return data
Handle 422s from the API on update requests too.
Move 422 creation test; update to stub model layer.

The test was in the "GET index" context, and was stubbing out responses
at the HTTP level, which is more the domain of integration tests.
Merge branch 'fix-404-bug'