Make tox config work.
Make tox config work.

Change-Id: Ic81c7bb0fa2fe5c73200a9195630a0d5bb999e7d

openstack/networking-plumgrid,fawadkhaliq/networking-plumgrid,fawadkhaliq/networking-plumgrid,msagheer/networking-plumgrid,stackforge/networking-plumgrid,msagheer/networking-plumgrid,openstack/networking-plumgrid,stackforge/networking-plumgrid