Dockerize iHat

REFERENCES
===
https://www.pivotaltracker.com/story/show/82965638

See the readme on the branch for installation instructions:

https://github.com/Tahi-project/iHat/blob/dockerize/README.md

TODO:

- [ ] [Open URL on successful boot](https://github.com/Tahi-project/ihat/pull/27#discussion_r21470287)
`Display the shell commands to set up the Docker client.`

Is that something that needs to be done? You've already added those things to the shell profile. Perhaps I'm missing something.