Constraints are ready to be used for tox.ini
Constraints are ready to be used for tox.ini

Per email[1] from Andreas, we don't need to hack at install_command
any longer.

[1] http://openstack.markmail.org/thread/a4l7tokbotwqvuoh

Change-Id: I89cdb17eed14d60f0d4eaae6284c53b63087546b

openstack/kosmos,openstack/kosmos