minor syntax error in tox.ini
minor syntax error in tox.ini

Change-Id: I476ea8f2cf4370e62b6b6b15d72b97beabe6677e

BjoernT/python-openstackclient,openstack/python-openstackclient,openstack/python-openstackclient,dtroyer/python-openstackclient,redhat-openstack/python-openstackclient,BjoernT/python-openstackclient,dtroyer/python-openstackclient,redhat-openstack/python-openstackclient