Upgrade your Heroku Apps to ruby 1.9.3!

I write most of my apps in 1.9.3 at the moment and was recently stymied by code that doesn't work on Heroku. Turns out heroku's cedar stack uses ruby 1.9.2 by default.

Thankfully, It's super easy to set the ruby version in your Gemfile! Now if only it supported .ruby-version files like rvm and rb-env!