default source in Gemfiles to :rubygems rather than hardcoding the URL
* I guess this would be the preferrable default for Bundler
* current version of Bundler converts :rubygems into 'http://rubygems.org', not https://,
and that will help those who are working on a very poor network environment that doesn't allow SSL
Revert "Merge pull request #8341 from amatsuda/bundle_source_rubygems"
This reverts commit 33b29e0, reversing
changes made to ac8c729.