OVN migration is missing python3 support

[Jakub Libosvar]

Description of problem:

OVN migration job is failing with error:
TASK [Install python virtualenv] ***********************************************
task path: /home/rhos-ci/jenkins/workspace/DFG-network-networking-ovn-15_director-rhel-virthost-3cont_2comp-ipv4-vxlan-ml2ovs-to-ovn-migration/infrared/plugins/tripleo-ovn-migration/migration/infrared/tripleo-ovn-migration/main.yml:6
Saturday 15 June 2019 21:50:24 +0000 (0:00:03.216) 0:00:03.420 *********
fatal: [undercloud-0]: FAILED! => {
    "changed": false,
    "failures": [
        "No package python-virtualenv available."
    ],
    "rc": 1,
    "results": []
}

MSG:

Failed to install some of the specified packages

 to retry, use: --limit @/home/rhos-ci/jenkins/workspace/DFG-network-networking-ovn-15_director-rhel-virthost-3cont_2comp-ipv4-vxlan-ml2ovs-to-ovn-migration/infrared/plugins/tripleo-ovn-migration/migration/infrared/tripleo-ovn-migration/main.retry

PLAY RECAP *********************************************************************
undercloud-0 : ok=1 changed=0 unreachable=0 failed=1

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/675884
Committed: https://git.openstack.org/cgit/openstack/networking-ovn/commit/?id=985f3805da9bed6477aa462f74d37c746c9bc2c6
Submitter: Zuul
Branch: master

commit 985f3805da9bed6477aa462f74d37c746c9bc2c6
Author: Jakub Libosvar <email address hidden>
Date: Mon Aug 12 12:22:13 2019 +0000

    migration: Use python3 packages when needed

    The patch changes names of installed packages by yum module based on
    what Python version of interpreter is available on given node.

    Closes-bug: #1839834

    Change-Id: I5a2409d80ebd19904909bd62fb7c11ae0cbfde30

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/stein
Review: https://review.opendev.org/677935

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/677935
Committed: https://git.openstack.org/cgit/openstack/networking-ovn/commit/?id=c4367485a18947bd204ce6ef72cc7d43890bfb3d
Submitter: Zuul
Branch: stable/stein

commit c4367485a18947bd204ce6ef72cc7d43890bfb3d
Author: Jakub Libosvar <email address hidden>
Date: Mon Aug 12 12:22:13 2019 +0000

    migration: Use python3 packages when needed

    The patch changes names of installed packages by yum module based on
    what Python version of interpreter is available on given node.

    Closes-bug: #1839834

    Change-Id: I5a2409d80ebd19904909bd62fb7c11ae0cbfde30
    (cherry picked from commit 985f3805da9bed6477aa462f74d37c746c9bc2c6)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/networking-ovn 7.0.0.0b1 development milestone.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/networking-ovn 6.0.1 release.