Update :has_many association declarations to use preferred scope bloc…

…k syntax for rails4 and prevent deprecation warnings. Close #211

lib/paper_trail/has_paper_trail.rb

@@ -58,9 +58,8 @@ def has_paper_trail(options = {})
         self.versions_association_name = options[:versions] || :versions
 
         has_many self.versions_association_name,
-                 :class_name => version_class_name,
-                 :as         => :item,
-                 :order      => "#{PaperTrail.timestamp_field} ASC, #{self.version_key} ASC"
+          lambda { |_model| order(PaperTrail.timestamp_field.to_sym => :asc, _model.class.version_key.to_sym => :asc) },
+          :class_name => self.version_class_name, :as => :item
 
         after_create  :record_create, :if => :save_version? if !options[:on] || options[:on].include?(:create)
         before_update :record_update, :if => :save_version? if !options[:on] || options[:on].include?(:update)

test/dummy/app/models/widget.rb

@@ -1,5 +1,5 @@
 class Widget < ActiveRecord::Base
   has_paper_trail
   has_one :wotsit
-  has_many :fluxors, :order => :name
+  has_many :fluxors, -> { order(:name) }
 end