timeutils.utcnow should be used instead of datetime.datetime.utcnow

[wangqun]

Use timeutils.utcnow to replace the datetime.datetime.utcnow

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/241871

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/241871
Committed: https://git.openstack.org/cgit/openstack/magnum/commit/?id=8c7925a018c9c6d86aa6f55537a69d8c6e749908
Submitter: Jenkins
Branch: master

commit 8c7925a018c9c6d86aa6f55537a69d8c6e749908
Author: wangqun <email address hidden>
Date: Thu Nov 5 04:44:59 2015 +0000

    timeutils.utcnow should be used instead of datetime.datetime.utcnow

    Developer should use timeutils.utcnow to replace the
    datetime.datetime.utcnow.

    Change-Id: Ifaca72e286a805632cd17406464175ba6819a9b0
    Closes-Bug: #1513308