Update documentation index to include Queens
Update documentation index to include Queens

Now that we have a release candidate available for Queens,
update the documentation index to include it.

Change-Id: I7d6d5fcbf02d66f77c055509007c1412a8d5e274

stackforge/os-ansible-deployment,stackforge/os-ansible-deployment,bunchc/openstack-ansible,openstack/openstack-ansible,openstack/openstack-ansible,bunchc/openstack-ansible