Wait for hypervisor-stats to reflect ironic nodes

When enrolling nodes into Ironic, poll nova's hypervisor-stats until
the hypervisor count reflects the number of enrolled nodes.  This
eliminates a race where devstack completes and an instance is spawned
before the first post-enrollment periodic task ticks on the Nova side,
which has recently started popping up in the gate.

Change-Id: Ib3d8005e0094ee8af2d5fcb65aca6cd92736da90
Closes-bug: #1398128
heat remove copy of sample config file

We're moving to a model like nova where we don't maintain a static
sample config, instead providing a readme showing how to generate
it in https://review.openstack.org/#/c/138800/, so this change
is needed before we can land that change.

Change-Id: I335a33646eef72962c9036dcd1de50144d8575c8
Merge "Wait for hypervisor-stats to reflect ironic nodes"