Updated openstack/openstack
Project: openstack/tempest  8b6aa092833b4736162a567ccd1fdd3c9fc6c8a2

Adds list users tests in v3

This submission adds test_list_users.py which has
list users with params test cases. Hence made changes
in client methods accordingly.

Change-Id: I264440772c2138ddbac74e68f227c6fb989c7b9f