Some unit tests were missing from the GitLab API v4 change. We had the

beginnings of a function for checking repositories against the v4 API,

but it never actually performed any checks (and was missing a necessary

part of the payload to make the checks happen).
This fills in the missing logic, and adds a utility function for setting

the API version for a test so spies don't need to be repeated in several

places.

Unit tests pass.