Include Docker recipes

[The9Cat]

Given the recent work on Docker, I suggest the following:

1. Rename this repo to EXP-container
2. Add the HPCCM docker recipe
3. Add documentation about the Docker build
4. Add the recently developed bash front-end script

Thought anyone?

[Mike, I've assigned this to you just to get your comments. Not suggesting that you need to do anything but provide feedback on this organization.]

[The9Cat]

PR #3 takes a stab at implementing this. Probably needs a bit more tutorial detail?

[The9Cat]

Provided more tutorial detail in the form of a Docker readme. I think everything is there more or less.

[The9Cat]

Done.