[devstack] switch to the latest API version and OSC commands
[devstack] switch to the latest API version and OSC commands

* Use only OSC commands instead of a mix of both CLI
* Switch to "latest" API version, as we're anyway going to use it by default
* Always set resource_class to something, as it's required since Pike

As a side effect, it enabled cleaning before nodes become available.

Change-Id: I36bf8d8204b0287a862a354760071ab3bdafbabc

openstack/ironic,pshchelo/ironic,pshchelo/ironic,openstack/ironic