Merge pull request #269 from dgraph-io/joaquin/makefile

Initial build/publish system for docker image artifact:

* makefile to build and push ratel docker image
* fixed issue with Dockerfile
* added package manifest in a separate docker image layer (best practices)
* added go-bindata install as separate docker image layer (best practices)
* run service in as unprivileged user dgraph (best practices)

Merge pull request #268 from dgraph-io/mbj36/bug-fix

bugfix: fix bug on userpane

Bump versions