Add extra unit tests for base_url

The implementation of base_url in auth.py allows for a generic path
to be included in the base_url before the version, however this is
not really enforced by unit tests yet. Adding them.

Change-Id: I4827f0fa9f6c501dcb0d9620434ab4e4c7a61fe1
Related-bug: #1591016
1 file changed