These are additions to make the Octavia Upgrade tests in the
charmed-openstack-tests repository a little easier to specify. Also
depends on the zaza change [1].
[1] https://github.com/openstack-charmers/zaza/pull/442
It's a bit too optimistic to expect an instance to respond to the first
ping. This patch gives the instance up to 8 retries with increasingly
lengthened waits to respond to a ping. This should help with Juju
storage backed nova instances.
Fixes: #265
