Adding ability to create stand-alone docker instance

[Eibwen]

Made a dockerfile to configure this. It runs both redis and node in the same docker instance (which is not the recommended way of using docker, but for such a simple app that is never going to get much load is not an issue)

(didn't realize github will append other commits on same branch to an existing pull request, so sorry for this second request after i deleted the first)

[crccheck]

I'm not sure if the Dockerfile should have redis in it. My choice would have been to only do the bot based on the official node base box and documentation showing how to link to the official redis docker image. In fact, now that I think about it, I don't like doing both in one.