Revert "updated Changelog "

This reverts commit 79990505.

Conflicts:

	activerecord/CHANGELOG

Reason: Sorry, CHANGELOGs can't be edited via docrails.

activerecord/CHANGELOG

@@ -237,13 +237,18 @@
   rails g model post user:belongs_to will generate the following:
 
     class CreatePosts < ActiveRecord::Migration
-      def change
+      def up
         create_table :posts do |t|
           t.belongs_to :user
           t.timestamps
         end
+
         add_index :posts, :user_id
       end
+
+      def down
+        drop_table :posts
+      end
     end
 
   [Santiago Pastorino]