Replace oslo_utils.timeutils.isotime
Replace oslo_utils.timeutils.isotime

Function 'oslo_utils.timeutils.isotime()' is deprecated in version '1.6'
and will be removed in a future version. We use
datetime.datetime.isoformat() instead. For more informations:
http://docs.openstack.org/developer/oslo.utils/api/timeutils.html#oslo_utils.timeutils.isotime

Change-Id: I3e4d1b8c09734be6c96e7e96ac4c72aa7b7cd454
Closes-Bug: #1514331

openstack/mistral,openstack/mistral,StackStorm/mistral,StackStorm/mistral