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
I don't understand. Thats why it's redirecting standard error to /dev/null. I'm not sure why it's sending non-error output to standard error, but yeah.

Perhaps we should change this to:

```
$(boot2docker shellinit &> /dev/null)
```