add balance promotion shop promotion

app/models/present.rb

@@ -6,6 +6,7 @@ class Present < ActiveRecord::Base
   belongs_to :wx_user
   SOURCE_ENUM = [["店长促销发放", "shop"],
                  ["充值促销发放", "balance"],
+                 ["手工添加", "others"],
                  ]
   def send_product
     prd1 = Product.where("id = ?", self.send_prod1).first