eliminate the need for hplefthandclient in tests

In order to eliminate the need to have the hplefthandclient in the
global-requirements project, we need to remove the hplefthandclient
from being imported in all HP LeftHand driver unit tests in cinder.

Change-Id: I4009ea17b507b1deb2a567dd420f309e15aaf92d
Closes-Bug: #1316824
Merge "eliminate the need for hplefthandclient in tests"