Add tests for identity endpoints

Change-Id: If15cc74fafbbe52fa86aa353f2598aa31daf0695
Closes-Bug: #1319450
replace string format arguments with function parameters

There are files containing string format arguments inside
logging messages. Using logging function parameters should
be preferred.

Change-Id: Ic749ac9eb55564ed631d57055a5a4dfc3aebd169
Merge "replace string format arguments with function parameters"
Merge "Add tests for identity endpoints"
Refactor role list subcommand for identity v3 api

Currently parts of user list and group list command are actually
functioning as role listing, which is quite counter intuitive and
misleading.

This refactor change move role related logic to a single place of role
list command. It now allows role grants listing for user/group +
domain/project combinations.

If no user or group specified, it will list all roles in the system,
which is the default behaviour.

Change-Id: I4ced6df4b76f018d01000d28b4281ad9f252ffcc
Merge branch 'timings' into dt-test