Fixes for UI arch and compute-resource related test-cases.

Can you call `create_json` instead of `create` here? The `create` method is currently a simple wrapper around `create_json`, but that will change in the future. At some point in the future, this method will return objects whose attributes can be accessed like so:

    entities.Organization().create().name

And the less work involved in making that transition, the better. :)