Fewer attributes paper trailed

app/models/event.rb

@@ -4,7 +4,8 @@
 class Event < ActiveRecord::Base
   extend SimpleCalendar
   strip_attributes
-  has_paper_trail ignore: [:secret, :submitter, :latitude, :longitude]
+  has_paper_trail ignore: [:last_updated, :secret, :submitter, :decision_time,
+                           :lock_version, :latitude, :longitude]
 
   belongs_to :region
   has_many :notes, dependent: :destroy