Public docker image live, updated docs

********* PEOPLE *************
Primary reviewer: @suntzu86 

Reviewers:

********* DESCRIPTION **************
Branch Name: sclark_332_set_up_public_docker
Ticket(s)/Issue(s): Closes #332 

********* TESTING DONE *************

Tested on dev and personal linux box
please note the following: if the docker containers aren't working and they want to build and old version locally, then after git clone:
```
git checkout tags/v0.1.0
```
(or w/whatever version) will grab what you want. ```git tag -l``` will list the options (or see them on: https://github.com/Yelp/MOE/releases)