update DOCKER_HOST ref

Author: Matthew Fisher

Dockerfile

@@ -3,11 +3,11 @@ MAINTAINER Jeff Lindsay <progrium@gmail.com>
 
 ADD ./stage/logspout /bin/logspout
 
-ENV DOCKER unix:///tmp/docker.sock
+ENV DOCKER_HOST unix:///tmp/docker.sock
 ENV ROUTESPATH /mnt/routes
 VOLUME /mnt/routes
 
 EXPOSE 8000
 
 ENTRYPOINT ["/bin/logspout"]
-CMD []
+CMD []