When an API resource depends on a feature, tests for it would pass or fail

depending on whether that feature was enabled in settings_local.py. Because

tests are there to test the actual behavior, we want to override the feature

status to enable it always.
This change does that, and fixes up the various mixins and top-level tests to

work correctly. I haven't added any extra tests to specific resources to verify

the API output when the feature(s) are disabled, because those are tested more

generically with a dummy resource and feature.

Disabled the status updates feature in my settings_local.py and ran unit

tests. Before this change, all the status updates tests failed. After, they

pass.