Allow tox to be able to run independent functional tests
Allow tox to be able to run independent functional tests

Allows tox to be able to run all functional tests in a Class as
well as a single functional test. Also runs the tests in verbose
mode, as is done in the gate.

Change-Id: I1fba43aa8c577c81da07522f84cddc36fd7807e1
Closes-Bug: #1514699

openstack/python-barbicanclient