Introduce strong parameters

app/models/splashpage.rb

@@ -1,8 +1,3 @@
 class Splashpage < ActiveRecord::Base
   belongs_to :conference
-  attr_accessible :public,
-                  :include_tracks, :include_program, :include_cfp,
-                  :include_venue, :include_registrations,
-                  :include_tickets, :include_lodgings,
-                  :include_sponsors, :include_social_media
 end