def update(cluster)
      deployed = primary_deployment(cluster)
      Ecs.update_service(cluster.name, name, register(deployed))
      name
    end
def update(cluster)
      deployed = primary_deployment(cluster)
      Ecs.update_service(cluster.name, name, register(deployed))
      name
    end
Register this task definition with ECS, and update the corresponding
 service.