ostestr --no-discover does not create subunit file

[Luz Cazares]

Having os-testr V.0.7.0 installed
When using ostestr with --no-discover option. TCs are successfully run but results file under .testrepository is not created.
Underneath ostestr, it is running command: "python -m subunit.run" instead of "testr run.

In order to keep consistency with testr, the expectation would be to store resulting subunit file unser .testrepository. This is writing the output to disk and pass it to stdout or subunit-trace at the same time.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/339189

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/339189
Committed: https://git.openstack.org/cgit/openstack/os-testr/commit/?id=054fb04f669d1edffce54fdb58d3dad17fae0a6d
Submitter: Jenkins
Branch: master

commit 054fb04f669d1edffce54fdb58d3dad17fae0a6d
Author: Luz Cazares <email address hidden>
Date: Thu Jul 7 11:51:46 2016 -0700

    Save subunit results file when using --no-discover

    When using ostestr --no-discover flag. The output subunit
    results file is not saved under .testrepository as it is
    when using testr run command.

    Change-Id: Ied6c5a46661b3b36bf15fd538bc6cac764fddcc8
    Closes-Bug: #1597111