enable arguments in tox

enable positional arguments in tox to allow nose flags to be set as
well as a subset of test to be run.

Change-Id: I46815aa395f6cac5e1fd9cb103871bbde6b8518f
fix volume tests to utilize VOLUME_DELETE notification

fix the volume tests to use correct notification message and
test for more values.

Fixes: bug #1160511
Change-Id: I870619e13d5c5bc10515f0401b8d4d6466c0f9fb
Merge "enable arguments in tox"
Merge "fix volume tests to utilize VOLUME_DELETE notification"