[RFE] Set up clouds.yaml in undercloud stack user

[Harald Jensås]

The openstack CLI and SDK support configuration using clouds.yaml.

Standalone deployments set up clouds.yaml. The undercloud should have a clouds.yaml with both the undercloud and the overcloud clouds defined.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/615853

[OpenStack Infra (hudson-openstack)]

Change abandoned by Alex Schultz (<email address hidden>) on branch: master
Review: https://review.openstack.org/615853
Reason: Clearing the gate. Do not retore this until being given the all clear. See http://lists.openstack.org/pipermail/openstack-discuss/2018-November/000368.html

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/615853
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=afa16ae150eef3c98c354c4ccc3cf872127c1c10
Submitter: Zuul
Branch: master

commit afa16ae150eef3c98c354c4ccc3cf872127c1c10
Author: Harald Jensås <email address hidden>
Date: Mon Nov 5 13:56:19 2018 +0100

    Create clouds.yaml for the undercloud

    Add the cloud to clouds.yaml for the undercloud so
    that it is available for post deploy script's.

    The clouds.yaml is created both in the stack users
    home directory ~/.config/openstack/clouds.yaml and
    globally for the system in /etc/openstack/clouds.yaml.

    Update standalone post configuration to use the same
    code to create and update clouds.yaml on standalone.

    clouds.yaml is used when setting up client's in other
    post scripts instead of passing all the options to
    each script.

    Partial-Bug: #1801927
    Change-Id: I6402fa561745bacf184b1ad2ada44bf8f7c75324