[Rkt](https://coreos.com/rkt) doesn't allow ports to be exposed to containers unless they are declared in the container manifest. Re-adding EXPOSE back in (removed inmaster^2
1dbf993bce) allows the container to be used on rkt based systems.
|@@ -123,3 +123,4 @@ RUN cd ~ && \|
|# Set the work dir and the container entry point|
|ENTRYPOINT ["/tini", "--"]|
|EXPOSE 3000 4000|