Remove Rails dependency

Move configuration into a Railtie.
Only dependency is now activemodel

lib/action_controller/serialization.rb

@@ -16,7 +16,7 @@ module ActionController
   #
   #    class ApplicationController < ActionController::Base
   #      private
-  #      
+  #
   #      def serialization_scope
   #        current_user
   #      end
@@ -48,4 +48,4 @@ module ActionController
       end
     end
   end
-end
+end

lib/active_model_serializers.rb

@@ -23,12 +23,10 @@ ActiveModel::Serialization.class_eval do
   end
 end
 
-require "action_controller"
-
-module ActionController
-  autoload :Serialization, "action_controller/serialization"
+begin
+  require 'action_controller'
+  require 'rails'
+  require 'railtie'
+rescue LoadError => ex
+  # rails on installed, continuing
 end
-
-ActiveSupport.on_load(:action_controller) do
-  include ::ActionController::Serialization
-end

lib/railtie.rb

@@ -0,0 +1,14 @@
+require 'active_model_serializers'
+require 'action_controller/serialization'
+
+module ActiveModel
+  module Serialization
+    class Railtie < ::Rails::Railtie
+      initializer "active_model.serialization.action_controller" do
+        ActiveSupport.on_load(:action_controller) do
+          include ::ActionController::Serilization
+        end
+      end
+    end
+  end
+end