This patch allows the user to perform the Inherited roles from projects API calls
through python-keystoneclient.
Assign role to user on projects in a subtree
PUT /OS-INHERIT/projects/{project_id}/users/{user_id}/roles/{role_id}/inherited_to_projects
List user's inherited project roles on project
GET /OS-INHERIT/projects/{project_id}/users/{user_id}/roles/inherited_to_projects
Check if user has an inherited project role on project
HEAD /OS-INHERIT/projects/{project_id}/users/{user_id}/roles/{role_id}/inherited_to_projects
Revoke an inherited project role from user on project
DELETE /OS-INHERIT/projects/{project_id}/users/{user_id}/roles/{role_id}/inherited_to_projects
These same operations regarding groups instead of users are also
available.
Change-Id: I8396d80f031726bbd23f2cc2bb302a7691f98cba
Closes-bug: 1446702