Upstream service which listens to unix domain socket

Kong version: 1.2.1

My current backend service (unicorn server) and nginx server communicate over a unix domain socket. When I am using kong for configuring nginx, I am unable to find any to get kong proxy the request to the unix domain socket instead of a normal IP path. My use case is that my backend service (Rails app running on Unicorn) is running on same machine as Kong.

Is there a way I could create a service which points to a local unix domain socket?