When people transition from three ironic nova-compute processes down
to one process, we need a way to move the ironic nodes, and any
associcated instances, between nova-compute processes.
For saftey, a nova-compute process must first be forced_down via
the API, similar to when using evacaute, before moving the associated
ironic nodes to another nova-compute process. The destination
nova-compute process should ideally not be running, but not forced
down.
blueprint ironic-shards
Change-Id: I33034ec77b033752797bd679c6e61cef5af0a18f