cloud-infra: Add basic verify jobs

cloud-infra: Add basic verify jobs

This change adds a multijob that gets triggered due to changes
coming to any of the projects listed below on Gerrit.

- infra/engine
- infra/swconfig

When the job gets triggered, it will trigger 2 multijob phases

- deploy: deployment of the stack using VMs will be done
- test: healthcheck of the deployed stack is done

If the main job or any of the phase jobs fail, the result will
be posted to Gerrit as Verified-1, blocking the change from
being merged to master.

It is expected that these jobs to evolve over time so they are
created only in order to have some basic verification in place.

The reason to choose multijob job type is that when a new patch
is published for an existing change, multijob aborts the build
that is running for the previous patch and starts a new build for
the new patch so this helps keeping things clean and tidy.

Change-Id: I21375ef2254e8b47ab2b5268366469f3d100fa99
Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>