Refactor document views specs

https://www.pivotaltracker.com/story/show/73291456
Summary of changes: https://docs.google.com/document/d/13TNmNkD6__d-7TbnvkNUV8yvCY8bc_SGa6ewxewrciE/edit?usp=sharing
Since `save_and_open_page` doesn't seem to work in view specs, what about the following as a cross-platform solution:

    def view_spec_page
      File.open('/tmp/test.html','w') { |file| file.write(rendered) }
      Launchy.open '/tmp/test.html'
    end