Finish up v3 role commands

* Remove Role
* List User-Role
* List Group-Role

Change-Id: I8673dd8221ef88978dada5a2833c187026bdb31a
dt updates to 27143

Remove the tweaks to utils.find_resource for domains; will address
that across domains, users and groups in another patch.
I want to nail down the structure of these commands and get that into place

Change-Id: Ie4e9a8dbf5b2a6daa3ea1cb926d4631dea780373
Merge branch 'py26-tests' into dt-test
Merge branch '27143-role-fix' into dt-test