Create 2014-11-25-ruby-2-2-0-preview2-released.md

file digests are still invalid
apply comments
Use preview-2's URLs and digests
Merge pull request #901 from nurse/ruby-2.2.0-preview2

Create 2014-11-25-ruby-2-2-0-preview2-released.md
bundle update
upgrade Ruby 2.1.5