Comment 8 for bug 1715325

Reviewed: https://review.openstack.org/501527
Committed: https://git.openstack.org/cgit/openstack/cloudkitty/commit/?id=07ba0dc64474dd66b87bbd3649fe6d3026cfaf80
Submitter: Zuul
Branch: master

commit 07ba0dc64474dd66b87bbd3649fe6d3026cfaf80
Author: chenghuiyu <email address hidden>
Date: Thu Sep 7 09:42:13 2017 +0800

    Utils: fix usage of iso8601_from_timestamp

    The commit Ib384ae8130dcc6cbd47a837d11ca171ce02ef29e replaced
    oslo_utils.timeutils.isotime, As oslo_utils.timeutils.isotime()
    is deprecated in version '1.6'. So the workaround is to copy
    the current implementation from oslo_utils.timeutils.isotime()
    to utils.py. However, oslo_utils.timeutils.iso8601_from_timestamp
    is also deprecated in version '1.6' and will be removed in a
    future version.

    So the workaround is to copy the current implementation from
    oslo_utils.timeutils.iso8601_from_timestamp() to utils.py

    For more informations:
    https://docs.openstack.org/oslo.utils/latest/reference/timeutils.html

    Change-Id: Iaea0465527329ac4253828fab88998de8eafc031
    Partial-Bug: #1715325