Making it work, fixes #1

[almereyda]

These commits look promising. Thanks @SimonSarazin for the mention.

• I will append a commit for the docker-compose.yml file, if it really works.
• Maybe we should create those credentials dynamically and pass them in a proper way?

[almereyda]

I'm too stupid for this. Still failing for me. Please have a look at https://github.com/istepanov/docker-hackpad/issues/1#issuecomment-143770177 if you mind helping out.