Basic support of Ironic

Ironic is an OpenStack project than brings a
separate service for baremetal provisioning.
Currently Ironic is in incubation but it needs
to have basic support in devstack to provide
automatic deployment testing.

Change-Id: Ide65a1379fa207a6c8b2c7d9a4f9c874b10fd9ba
Merge "Basic support of Ironic"
Merge branch 'master' of github.com:openstack-dev/devstack