Move Cinder admin tests into unversioned path

As http://lists.openstack.org/pipermail/openstack-dev/2017-March/114507.html
we will use the existing Cinder V2 API tests for testing the base
microversion of Cinder V3 API also.
So it is not necessary to contain versioned path in test module pathes.
This patch just moves Cinder admin tests to unversioned pathes.

Change-Id: I2acfe5a28a2533b16565e6ebad5c820e7c3a3967
8 files changed