Finish small unit test refactor of API v2 tests
Finish small unit test refactor of API v2 tests

Leverage a utility function for all of the tests
that create something in the API and expect a failure.

Change-Id: Iedb6ba35d637dda5ae9f553d0c7ffcb7c526f3c6

gkotton/vmware-nsx,gkotton/vmware-nsx