Fixed bug order.profit calculation.

Order.profit will also be saved, when order is closed.

test/unit/article_price_test.rb

@@ -1,3 +1,17 @@
+# == Schema Information
+# Schema version: 20090317175355
+#
+# Table name: article_prices
+#
+#  id            :integer         not null, primary key
+#  article_id    :integer
+#  price         :decimal(8, 2)   default(0.0), not null
+#  tax           :decimal(8, 2)   default(0.0), not null
+#  deposit       :decimal(8, 2)   default(0.0), not null
+#  unit_quantity :integer
+#  created_at    :datetime
+#
+
 require 'test_helper'
 
 class ArticlePriceTest < ActiveSupport::TestCase