Remove cinderclient version pin
Remove cinderclient version pin

We had put this in because of the v2 version negotiation breaking public
clouds. That has since been fixed, and the pin here causes conflicts
with python-openstackclient.

Change-Id: I9ee2d9bfad36160ba41f65dcd657cbbca9f26050

openstack/python-openstacksdk,stackforge/python-openstacksdk,openstack-infra/shade,openstack/python-openstacksdk,dtroyer/python-openstacksdk,stackforge/python-openstacksdk,openstack-infra/shade,dtroyer/python-openstacksdk