This fixes the bug where creation of consistency snapshot would pass
even if the volume is in error state. Also adding unit test to
ensure that the creation of consistency snapshot fails when
volume is in error status.
Closes-Bug: #1592451
Change-Id: I482a7e01f32d72196568348225eb3c77a432a539
Signed-off-by: Nitin Madhok <nmadhok@g.clemson.edu>