rubygems/rubygems.org — pull request #415 by george (2012-04-12 18:25:49+00:00)
Title: Bundler installation instructions use single quotes as opposed to double...

....

Most ruby style guides prefer single quotes over double except in cases where
interpolation or special characters (e.g. \t or \n) are needed, which likely
isn't the case for Gemfiles.

Thanks for your consideration.