Move tests in keystoneclient

This is the suggested location for tests and is adopted by most
projects. As part of this change relative imports to package imports.

Fix all the test running and coverage code to point to the new location.

Change-Id: I01264aed14f396ab9a7242e3e72b71e1bc332675
Require oslo.config 1.2.0 final

Now that 1.2.0 has been released, require it rather than on of the beta
release tarballs.

Closes-Bug: #1182861
Change-Id: I75ffc4a572d14488d19491a38742d6920951c171
Merge "Move tests in keystoneclient"