Adds create volume from image test

This is implemented by reusing the existing code written
for volume_create_get_delete; that function has been renamed
and has support for an the parameter 'image_ref'. The pre-existing
volume_create_get_delete as also the new volume_from_image call
the now renamed old function.

Change-Id: I08e69560e68b8f9a47d96d4446c35a670e17d1a9
Implements: blueprint add-volume-creation-from-image
Merge "Adds create volume from image test"