We are now working with a common .ini file for running a development server and for running py.test.
In-progress change to fully utilize py_gnome’s update_from_dict method.
Refactored the common create and update method.

Refactored the create and update methods.
- both functions now use a common tree iteration method
- update() now uses the py_gnome object's update_from_dict().
updated policy to include the staging server client installation
Added a unit test that creates a model with a spill, and then removes the spill
Added a unit test to cover a adding a sparse object to a model and then updating the model.
in-progress: trying to get the http exceptions to have the same cors headers as the rest of the responses.
in-progress: http exceptions need to have the same cors headers as the rest of the responses.
Added a unit test to validate updating a spill that contains a sparse element type
Added a unit test to validate updating a model with a nested sparse spill.
Added tests that verify updating a model that contains a sparse mover.  Added such tests for all mover types.