Update to rubyzip affects selenium-webdriver

[Neil-Aframe]

API of rubyzip has changed with latest version. Please see: https://github.com/rubyzip/rubyzip

This has caused a few people I suspect to have this problem when creating new projects, when they rely on listing their direct dependency on selenium-webdriver in their Gemfile, and not listing a version for rubyzip:

lib/selenium/webdriver/common/zipper.rb:1:in `require': cannot load such file -- zip/zip (LoadError)

Also see http://stackoverflow.com/questions/18555992/bundle-exec-rspec-spec-requests-static-pages-spec-rb-from-hartls-tutorial-isnt

[Neil-Aframe]

Closing this in favour of Pull Request.