Look into reducing base image size

[fgrehm]

Maybe use debian:jessie as a starting point or even https://github.com/docker-library/docker-buildpack-deps (https://registry.hub.docker.com/_/buildpack-deps/)

[fgrehm]

Switching to progrium/cedarish:cedar14 lowered the base image from 1.168GB to 867.7MB for v0.2.0, we can lower it even more by removing nodejs, bazaar, mercurial and possibly other stuff from the base and I'll look into it on 0.3.0