This patch add a murano_auth for murano auth with keystone,
This gives ability to fine-tune role-based privileges for
service-user going to execute trust-delegated tasks and the auth
configuration properties do not need to change when keystonemiddleware
deprecates its configuration properties.
Closes-Bug: #1643583
Closes-Bug: #1658648
Change-Id: If10fa8c938c264c7b5cadb3c3ed77f39488dcab7