Kolla Ansible train deploys master containers by default

[Mark Goddard]

In stein and earlier releases, we set openstack_release to 'auto'. This would detect the version of kolla-ansible and use it as the container tag. On master, we then changed this to 'master', with the intention that it would be changed on each stable branch prior to release. However, as this was a new part of the release process, we forgot to do it for Train. This results in kolla-ansible using the 'master' images by default.

The same is true for kolla_source_version, which affects the version of repos used in dev mode.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/train
Review: https://review.opendev.org/711214

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/711214
Committed: https://git.openstack.org/cgit/openstack/kolla-ansible/commit/?id=c61d0af87c1d8ec8eb6897de0cef426a0c74dfee
Submitter: Zuul
Branch: stable/train

commit c61d0af87c1d8ec8eb6897de0cef426a0c74dfee
Author: Mark Goddard <email address hidden>
Date: Wed Mar 4 12:15:54 2020 +0000

    Set openstack_release and kolla_source_version to train

    In stein and earlier releases, we set openstack_release to 'auto'. This
    would detect the version of kolla-ansible and use it as the container
    tag. On master, we then changed this to 'master', with the intention
    that it would be changed on each stable branch prior to release.
    However, as this was a new part of the release process, we forgot to do
    it for Train. This results in kolla-ansible using the 'master' images by
    default.

    The same is true for kolla_source_version, which affects the version of
    repos used in dev mode.

    This change sets openstack_release and kolla_source_version to 'train'.

    Also included in this patch is a fix for ARA on Python 2:

    pyfakefs 4.0.0 dropped support for Python 2. It is used by the ARA
    callback plugin.

    Change-Id: Ia0dc783929769c7c2dae5aaaad7d51c7de0e2b10
    Closes-Bug: #1866054
    Closes-Bug: #1866079