Replace assertTrue with explicit assertIsInstance

assertIsInstance can provide useful message when test fails,
this patch replaces assertTrue(isinstance(x, y)) with
assertIsInstance(x, y).

Change-Id: I1a36b4f343c881b6690389753270d35599b758ab
Closes-Bug: #1268480
Respect region name when processing domain URL

When deprecating the use of management_url from service_catalog we
updated the management_url setter for the project scoped token, however
we missed the domain scoped token case.

There is actually nothing we can do here to test this scenario as the
backwards compatibility code that was installed handles this for us and
there is no problem, however we should not be internally relying on
deprecated code.

Change-Id: I59bac4d9d74f2eb8bc6edd40518c7cd5a4fe1343
Merge "Replace assertTrue with explicit assertIsInstance"
Merge "Respect region name when processing domain URL"