In Route, add capability for watching for changes to Configuration so when Configuration gets updated, we'll pick up changes)

[dewitt]

[vaikas]

PR #104 added watches for the Revision watching Endpoints. We should do something similar for the ElaService watching RevisionTemplates and when Status.Latest changes if the traffic is set to follow a RevisionTemplate, we should update the routerules to point to newly ready k8s service that the new Revision has.