This patch refactors volumeops.py to use os-brick for volume
related operations.
The immediate benefits are:
* FC support
* improved iSCSI MPIO support
* simplified volume connect/disconnect workflow
Change-Id: Ib21947141aadca1fa6cb99afc07a175ce14d192e
Depends-On: I19dfc8dd2e9e8a1b17675b55c63de903804480e4
Implements: blueprint hyperv-use-os-brick