Merge rubygems master branch from github.com/rubygems/rubygems.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65294 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Merge rubygems master branch from github.com/rubygems/rubygems.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65294 b2dd03c8-39d4-4d8f-98ff-823fe69b080e