TheOdinProject/curriculum — pull request #402 by hbaughman (2014-07-30 16:44:29+00:00)
Title: Heroku app names may not contain underscores

$ heroku rename my_cool_app
Renaming fierce-ravine-2915 to my_cool_app... failed
! Name must start with a letter and can only contain lowercase letters, numbers, and dashes.