Fixes hpelefthandclient AttributeError
Fixes hpelefthandclient AttributeError

Adds check during setup in hpe_lefthand_iscsi.py to see if
python-lefthandclient is installed.

Change-Id: Ia2dce33e0f72132167edeccdefa46d253f40c2cd
Closes-Bug: #1525321

eharney/cinder,phenoxim/cinder,eharney/cinder,openstack/cinder,phenoxim/cinder,mahak/cinder,ge0rgi/cinder,openstack/cinder,Datera/cinder,Datera/cinder,mahak/cinder,j-griffith/cinder,j-griffith/cinder