http请求方式：POST
https://api.weixin.qq.com/product/delivery/get_company_list?access_token=xxxxxxxxx

{
    "errcode": 0,
    "errmsg":"ok",
    "company_list":
    [
        {
            "delivery_id": "SF",
            "delivery_name":"顺丰速运"
        },
        {
            "delivery_id": "YTO",
            "delivery_name":"圆通快速"
        },
        {
            "delivery_id": "ZTO",
            "delivery_name":"中通快速"
        },
        ...
    ]
}