Add auth_uri in conf to avoid unnecessary warning

Unittest code for auth_token.py doesn't specify auth_uri in conf,
which will cause lots of warnings, since auth_token.py will use
'%(protocol)s://%(host)s:%(port)s' to generate auth_uri when it is
None, we can specify this value directly to avoid unnecessary warnings.

Closes-Bug: #1219493
Change-Id: I26b636bcddabd91b06479c6a42a6a48d74ac9431
Merge "Add auth_uri in conf to avoid unnecessary warning"