Run py35 gate not on stable/newton for requirements and murano-agent
Run py35 gate not on stable/newton for requirements and murano-agent

This job does not pass on stable/newton for these two repositories.

Since it passes on master, keep it voting and disable it for the older
branches.

Change-Id: I34ec35fe3f66ac369c0c49897e1b88d0504e6364

openstack-infra/project-config,openstack-infra/project-config