Use image native api in volume tests

Image APIs in compute has been deprecated, just like volume extension
(os-volumes, os-snapshots), networks(os-networks), etc. Image native APIs
are recommended. And Glance V1 APIs are deprecated and v2 are current.
This patch substitue the old compute_image_client and remove Glance v1
APIs in volume tests, just use Glance v2 APIs.

Change-Id: I2cbae9775d54da40cc6af8a247a8113dde2a5579
4 files changed