Add support for volume v2 API
Add support for volume v2 API

Added following commands for volume V2 API:
volume show
volume delete
volume type show
volume type delete
snapshot show
snapshot delete
backup show
backup delete

Implements: blueprint volume-v2
Change-Id: I68bd303c194f304ad15f899d335b72a8bf3ebe10

dtroyer/osc-lib