Created slack team for Auton

[Terrence Wong]

A few months ago some of us started using Slack for coordination and it 
seemed pretty useful, especially since our group is so spread out.

If you would like to join the Auton slack team, please go here:
https://auton.slack.com/signup

andrew.cmu.edu and cs.cmu.edu email addresses should be able to join 
automatically. I can invite any other addresses.

Terrence