Enable keystone authentication in Ironic

Currently Ironic installation script leaves authenticaiton
strategy in its default value which is noauth. This is not
relevant for the most of development and testing environments.

This patch sets authentication strategy for Ironic to keystone
and specifies the path to the policy file.

Closes-bug: #1233612
Change-Id: Idacbda05663e7ef949cbce0dbdf28eaa36b6a1a9
Merge "Enable keystone authentication in Ironic"