创建商家券 
商户可以通过该接口创建商家券。
js
wxpay.v3.marketing.busifavor.stocks.post({
  stock_name,
  belong_merchant,
  comment,
  goods_name,
  stock_type,
  coupon_use_rule,
  stock_send_rule,
  out_request_no,
  custom_entrance,
  display_pattern_info,
  coupon_code_mode,
  notify_config,
  subsidy,
})
.then(
  ({ 
    data: {
      stock_id,
      create_time,
    },
  }) => ({
    stock_id,
    create_time,
  })
)