uncap python-keystoneclient version requirement

if any of the projects specify a capped client, it has the
potential for preventing that client from being tested in the
gate. To fix this we have to uncap maximum versions of all
openstack client code in all openstack projects.

Fixes bug #1200214

Change-Id: I664d2f030972a3bbb08ae1c4b1710816b54b44b2