resolve KeyError for IBM Storwize/SVC driver

When using iSCSI protocol to conenct IBM v7000, and compression
is not enabled for the system, KeyError may occur because of the response
item's lack of 'license_compression_enclosures'. So add a check to
resolve it.

Change-Id: Ie53631ea5b047650897313ad5614f6e1df5377f2
Closes-Bug: #1288645
Simplify test force delete snapshot unit test

Make this test simple in just verifying if we have a snapshot and we do
a force delete that we get back an ok response from the controller.
Removing out RPC call and verifying snapshot was deleted since that's
out of the scope here.

Closes-Bug: #1291108
Change-Id: If10b1057cf170e77527a0933a1ddf1a6a59baa1d
Merge "resolve KeyError for IBM Storwize/SVC driver"
Merge "Simplify test force delete snapshot unit test"
(Test commit) Change README to reflect Jio's fork of Cinder

Change-Id: I3f26c0a736e63725aec24ca2fa12c707b8e6460f