Comment 16 for bug 1726399

Reviewed: https://review.openstack.org/518953
Committed: https://git.openstack.org/cgit/openstack/ospurge/commit/?id=af88d16028e2e266a62028fe1927c61d80c68b8c
Submitter: Zuul
Branch: master

commit af88d16028e2e266a62028fe1927c61d80c68b8c
Author: Victor Stinner <email address hidden>
Date: Fri Nov 10 16:40:45 2017 +0100

    Python2: Fix tox -e py27

    With this change, unit tests now pass on Python 2.7: tox -e py27.

    Changes:

    * Replace "yield from ..." with "for item in ...: yield item"
    * Remove last annotations from utils.py
    * tox.ini: use python3 as basepython rather than python3.5 to support
      Python 2.7 and Python 3.6
    * tox.ini: add py27 to envlist

    Related-Bug: 1726399
    Change-Id: Ief1a95402e8a31a34ada2937a7ae6a604f7f8757