Nova ironic driver review update requests to p4

In https://review.openstack.org/#/c/111425/7/nova/tests/virt/...
...ironic/test_driver.py it was requested to change the way API
testing was conducted.  In doing this, some slight alterations
have been needed to ensure conformity.

Change-Id: Ia2905e4a8a27ff196198e35d04d0570065d2779d
Merge "Nova ironic driver review update requests to p4"