ubuntu: start gating on Ocata packages
ubuntu: start gating on Ocata packages

It seems like Canonical now provides packaging for Ocata release:
http://ubuntu-cloud.archive.canonical.com/ubuntu/dists/xenial-updates/ocata/main/

Let's use them.

Change-Id: I83c7c909074698ef87b52eb5e2b1cec1fb4cc26d

openstack/puppet-openstack-integration,openstack/puppet-openstack-integration,openstack/puppet-openstack-integration