Set ansible's default branch to devel
Set ansible's default branch to devel

This is, in fact, the default branch for that project, rather than
'master', so tell Zuul about that so that it checks out the "right"
one by default.

Change-Id: Ie029b7e0e0e2430a4555c8ed198bf370054af428

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