timeutils: considers that now is soon

This is a follow-up to Doug suggestion at

     https://review.openstack.org/#/c/20323/2/openstack/common/timeutils.py

Change-Id: Ic318202234202e56054df1b5cc7f82a404c307bc
Signed-off-by: Julien Danjou <julien@danjou.info>
Merge "timeutils: considers that now is soon"