Can't parse python-novaclient!=2.21.0,>=2.18.0

[Derek Higgins]

As of about 10:30 UTC today all non puppet tripleo tests started failing with

2015-02-20 03:49:27.993 | + heat stack-create -e /opt/stack/new//overcloud-env.json -t 360 -f /opt/stack/new//tripleo-heat-templates/overcloud.yaml -P ExtraConfig= overcloud
2015-02-20 03:50:28.909 | ERROR: Timed out waiting for a reply to message ID a9feb23034da44a7b39547d8d8eecefc.

Looks like it started then this update to requirements merged
https://review.openstack.org/#/c/157643/

Here is the error from the heat-engine log
Feb 20 06:18:05 ubuntu heat-engine: 2015-02-20 06:18:05,593 CRITICAL Could not load AWSTemplateFormatVersion.2010-09-09: (python-novaclient 2.21.0 (/opt/stack/venvs/openstack/lib/python2.7/site-packages), Requirement.parse('python-novaclient!=2.21.0,>=2.18.0'))

[Steven Hardy (shardy)]

I did some local testing, and I think this is fixed by upgrading six:

https://review.openstack.org/157764

[OpenStack Infra (hudson-openstack)]

Change abandoned by Derek Higgins (<email address hidden>) on branch: master
Review: https://review.openstack.org/157869
Reason: No longer needed

[Derek Higgins (derekh)]

Yup, looks like this was fixed by the updated six