Fixed bug where JSON params were not being processed.
Set request method for create and edit user tests.
Confirm create and edit user responses use the edit context.  Related #664
Move logic for checking create or edit users response into separate method.
Add test for creating new user with JSON.
Add new skipped test for updating user with JSON.
Merge pull request #675 from WP-API/two-users-fix-param-checks

Fix parameter handling and improve Users Controller tests