If I add nokogiri-diff to my Gemfile and do a bundle install, I get:
Bundler could not find compatible versions for gem "nokogiri":
In Gemfile:
nokogiri-diff (>= 0) ruby depends on
nokogiri (~> 1.4.1) ruby
cucumber-rails (>= 0) ruby depends on
nokogiri (1.5.0)
If I add nokogiri-diff to my Gemfile and do a bundle install, I get: