CI: Add Neutron to required-projects list
CI: Add Neutron to required-projects list

Unit tests jobs (openstack-tox-py3x) are better to run with latest
Neutron otherwise they can fail till a new Neutron release is out.

Change-Id: I83cb8ca8969567f0383f6842ccf66e1864e0a715

openstack/neutron-vpnaas,openstack/neutron-vpnaas