v2 auth - return an endpoint when no region is given

Previously when a user did not specify a region, only an endpoint with an empty region field would be used. This change is in line with python-keystoneclient behavior and removed the need for a blank region field in the service catalog
Typo - missing equals in variable declaration
Merge pull request #42 from its-not-a-bug-its-a-feature/patch-1

v2 auth - return an endpoint when no region is given