public function up()
 {
     $this->createTable('shipping_discount', ['id' => $this->primaryKey(), 'shipping_option_id' => $this->integer()->notNull(), 'discount_id' => $this->integer()->notNull()]);
     $discountType = new DiscountType();
     $discountType->name = 'Shipping Discount';
     $discountType->class = 'app\\modules\\shop\\models\\ShippingDiscount';
     $discountType->active = 1;
     $discountType->checking_class = 'Order';
     $discountType->sort_order = 0;
     $discountType->add_view = '@app/modules/shop/views/backend-discount/_shipping_discount';
     $discountType->save();
 }