Explicit mention py2 for neutron-grenade job
Explicit mention py2 for neutron-grenade job

Devstack is moving to py3 by default[1] and neutron-grenade
will fail. There are patches up to drop the neutron-grenade
job but those are not merged yet.

let's keep this job runnable by explicitly mention the py2
and dropping plan will continue as it is.

[1] http://lists.openstack.org/pipermail/openstack-discuss/2019-November/010938.html

Change-Id: I086b5eee710b80e95703abb46a076aff5b7741f2

openstack/neutron,mahak/neutron,mahak/neutron,openstack/neutron,openstack/neutron,mahak/neutron