Comment 23 for bug 1744160

Reviewed: https://review.openstack.org/535608
Committed: https://git.openstack.org/cgit/openstack/glance/commit/?id=daa3c88d8b824207577cfd5a17ee54edc786bba2
Submitter: Zuul
Branch: master

commit daa3c88d8b824207577cfd5a17ee54edc786bba2
Author: deepak_mourya <email address hidden>
Date: Fri Jan 19 11:14:32 2018 +0530

    Handle TZ change in iso8601 >=0.1.12

    The iso8601 lib introduced a change such that if running on python
    3.2 or later it internally uses the python timezone information
    instead of its own implementation. This does not change direct
    date handling, but when converting this value there is a slight
    difference where now python 2.x will show UTC times as "UTC",
    but on python 3 they will end up with "UTC+00:00".

    The to_primitive call for DateTime fields was doing an exact match
    on "UTC" to determine whether to include "Z" in the resulting string.
    This updates that handling to recognize either of the new values

    Change-Id: Icb29d71472932f3ddfe485298d1a5fdd08be6f12
    Closes-bug: #1744160