sethvargo/bootstrap_forms — pull request #79 by christophemaximin (2013-03-30 23:39:22+00:00)
Title: Replaced deprecated `source :rubygems' with recommended `source "https://rubygems.org"'

As said by Bundler when you're installing the gems:

The source :rubygems is deprecated because HTTP requests are insecure.
Please change your source to 'https://rubygems.org' if possible, or 'http://rubygems.org' if not.