Address bug 1839794 on the Volume show version client

Bug https://bugs.launchpad.net/tempest/+bug/1839794
found out that the volume version_show client that
was not used had a defect when builing the URL.
Used the same direction that the compute version client
did to strip off the version and project info and add
back the version.[0] Also added a Volume v3 test using the
client.

[0] https://github.com/openstack/tempest/blob/master/tempest/lib/services/compute/versions_client.py#L40

Change-Id: I9be99f5fc0eab3de125ce69415a0be65b1c4ad0d
Closes-Bug: #1839794
3 files changed