Skip any changed attributes marked to skip in the PaperTrail options …

…- helps to resolve #224

lib/paper_trail/has_paper_trail.rb

@@ -262,7 +262,7 @@ def item_before_change
         end
         previous.tap do |prev|
           prev.id = id
-          changed_attributes.each { |attr, before| prev[attr] = before }
+          changed_attributes.except(*self.class.paper_trail_options[:skip]).each { |attr, before| prev[attr] = before }
         end
       end