rails/rails — pull request #16046 by grosser (2014-07-04 00:33:07+00:00)
Title: Do not load rails without loading bundler

This if File.exist seems like a bad idea / let's people run into weird issues when the Gemfile is missing (deploy messed up / deleted by accident / BUNDLE_GEMFILE pointed to invalid file etc).
Users that do not want bundler can just remove the require.

@josevalim @rafaelfranca