add migrate wx_user function

go/gopath/src/fohow.com/apps/models/user_model/init.go

@@ -5,5 +5,6 @@ import (
 )
 
 func init() {
-	orm.RegisterModel(new(Session), new(User), new(WxUser), new(InviteOrder), new(WxUserGongzhonghao), new(ThreeWxUser), new(ShopApplication))
+	orm.RegisterModel(new(Session), new(User), new(WxUser), new(InviteOrder), new(WxUserGongzhonghao),
+		new(ThreeWxUser), new(ShopApplication), new(BindUser))
 }