Replace the python script that was run on post-config, by an Ansible
task running on the host where Keystone is running.
It'll be useful later when using OpenStackSDK to have access to the
credentials during the deployment and not having to wait the far end.
It's also reducing the Heat resources.
(cherry picked from commit 25a2045e62)
This change adds scenario012-standalone to the list of scenarios, copied
from the scenario012 multinode and translate for use with standalone
Scenario012 multinode was overriding the standard standalone-post
template, to run specific configuration commands to test ironic with
tempest, so a new post template was created, that includes both post