Then /^the page should be valid/ do
  Tidy.path = '/usr/lib/libtidy.dylib'
  xml = Tidy.open(:show_warnings => false) do |tidy|
    xml = tidy.clean(response.body.to_s)
    tidy.errors.each do |e|
      e.to_s.split(/\n/).each do |err|
        err = Tidyerr.new(err)
        unless err.message =~ /trimming empty <[a-zA-Z]+>/
          raise "HTML Validation error: #{err.message} at line #{err.line}:#{err.column}: #{response.body.split("\n")[err.line - 1]}"
        end
      end
    end
  end
end