Rails 4 compatibility

lib/draper/decorator.rb

@@ -1,10 +1,11 @@
 require 'active_support/core_ext/array/extract_options'
+require 'active_model/serialization'
 
 module Draper
   class Decorator
     include Draper::ViewHelpers
     extend Draper::Delegation
-    include ActiveModel::Serialization if defined?(ActiveModel::Serialization)
+    include ActiveModel::Serialization
 
     # @return the object being decorated.
     attr_reader :source

spec/dummy/bin/rails

@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+APP_PATH = File.expand_path('../../config/application',  __FILE__)
+require_relative '../config/boot'
+require 'rails/commands'