title: NoMethodError - undefined method `timestamp_sort_order' for Paper trail issue after upgrading Rails 4.2
body: <p>I used paper_trail to tracking transnational changes when I migrated rails 3.2 to rails 4.2, have got below issue:</p>
  
  <blockquote>
    <p>NoMethodError - undefined method `timestamp_sort_order' for</p>
  </blockquote>