Remove validate_location

As part of the fix for bug 1334196 Glance no longer uses the
'validate_location' function. (https://review.openstack.org/#/c/107383/)

It can be removed from the store.

Change-Id: Ib45f2d5d04bf28b8dfe9c5e879f910514f330950
Move cinder store to use auth_token

The cinder store uses auth_tok. This should be
changed to use auth_token as the glance request
context is changing: https://review.openstack.org/#/c/131478/

Change-Id: Id8a920d7035de111ce3fde54d62f35a07a9a7851
Partial-bug: #1385213
Merge "Move cinder store to use auth_token"
Merge "Remove validate_location"