Robot

Refactor robot_name.rb according to last comments
I'm trying to think of how to change this cleanly, but the two options I'm coming up with are:
1. Remove the string, since the error is already a custom error and the text does not really buy you anything and makes it a bit harder to globalize.
2. Create an unless valid && uniq block
3. (And maybe even 3) make valid? && uniq? check @name directly.