glance and keystone for havana

First, thanks for your openstack-ansible-modules, it has helped us really a lot. 

I'm now working on modifying it to make it work for havana release. Unfortunately the "gettextutils.install('glance')" will probably break the openstack-ansible-modules for grizzly release, so I was wondering if you would prefer if I put some try/except around it (which I think is an ugly thing to do just to avoid a bug) or if you would prefer to create a new branch for havana release (that's what I did on my fork of your repository). 

Please have a look at my commits and tell me what you think,

Thanks