Nova do not wait for cleaning is completed when deleting instance
as result after destroy phase ironic may still perform cleaning.
This patch ensures all nodes are available again after base smoke tests
finished and hypervisor stats are updated.
We still need to wait for resources after destroy phase which will be
done in separate patch as changes to grenade workflow are needed.
Change-Id: Ib6c5a0543533893664cb3e895286d0e226e364d2
bf91a8fca4