当用户和公众号产生特定动作的交互时（具体动作列表请见下方说明），微信将会把消息数据推送给开发者，
开发者可以在一段时间内（目前修改为48小时）调用客服接口，通过POST一个JSON数据包来发送消息给普通用户。
此接口主要用于客服等有人工消息处理环节的功能，方便开发者为用户提供更加优质的服务。
//config配置文件省略...
wc := wechat.NewWechat(config)
kf := wc.GetCustom()
//增加客服账号 账号，昵称
re,err := kf.AddKfAccount("zhangsan@test", "小宜")
//修改客服账号
re,err := kf.UpdateKfAccount("zhangsan@test", "小宜2")
//删除客服账号
re,err := kf.DelKfAccount("zhangsan@test2")
//获取客服列表
re,err := kf.GetKfList()
//获取在线客服列表
re,err := kf.GetKfOnlineList
//邀请绑定客服帐号 参数 客服账号，微信号
re, err := kf.InviteWorker("zhangsan33@test","ppwqer-102")
//设置客服头像 账号，用FORM表单方式上传一个多媒体文件
re,err := kf.SetHeadImgURL("zhangsan@test","./util/upload/test.jpg") //文本消息
text := custom.NewText("客服文本消息发送测试") //文本
text.ToUser = "oEYzpw3sceZnppwqerybyzNdWL3Ic" //toUser
text.MsgType = "text" //类型
text.CustomService.KfAccount = "zhangsan@test" //指定客服账号
re,err := kf.SendMsgByKf(text)
//图片消息
img := custom.NewImage("123124435245") //mediald
img.ToUser = "abcd1234abcd1234abcd1234"
img.MsgType = "image"
img.CustomService.KfAccount = "zhangsan@test"
re,err := kf.SendMsgByKf(img)
fmt.Println(re,err)
//语音
voice := custom.NewVoice("mediald")
voice.ToUser = "abcd1234abcd1234abcd1234"
voice.MsgType = "voice"
voice.CustomService.KfAccount = "zhangsan@test"
re,err := kf.SendMsgByKf(voice)
//视频
video := custom.NewVideo("mediald", "thumbMediald", "title","description")
video.ToUser = "abcd1234abcd1234abcd1234"
video.MsgType = "video"
video.CustomService.KfAccount = "zhangsan@test"
re,err := kf.SendMsgByKf(video)
//音乐
music := custom.NewMusic("title", "des cription", "musicURL", "HQMusicUrl", "thumbMediald")
music.ToUser = "abcd1234abcd1234abcd1234"
music.MsgType = "video"
music.CustomService.KfAccount = "zhangsan@test"
re,err := kf.SendMsgByKf(music)
//图文 发送图文消息（点击跳转到外链） 图文消息条数限制在1条以内，注意，如果图文数超过1，则将会返回错误码45008。
ar := custom.NewArticle("图文消息", "我是一条图文消息", "https://www.baidu.com/img/bd_logo1.png", "")
var newsList []*custom.Article
newsList = append(newsList, ar)
ars := custom.NewNews(newsList)
ars.ToUser = "abcd1234abcd1234abcd1234"
ars.MsgType = "news"
ars.CustomService.KfAccount = "zhangsan@test"
re,err := kf.SendMsgByKf(ars)
//mpnews 发送图文消息（点击跳转到图文消息页面） 图文消息条数限制在1条以内，注意，如果图文数超过1，则将会返回错误码45008。
mpnews := custom.NewMpNews("mediald")
mpnews.ToUser = "abcd1234abcd1234abcd1234"
mpnews.MsgType = "video"
mpnews.CustomService.KfAccount = "zhangsan@test"
re,err := kf.SendMsgByKf(mpnews)
//卡券
card := custom.NewCard("cardid")
card.ToUser = "abcd1234abcd1234abcd1234"
card.MsgType = "video"
card.CustomService.KfAccount = "zhangsan@test"
re,err := kf.SendMsgByKf(card)
//小程序卡片
minipg := custom.NewMiniProgramPage("title","appid","pagepath","thumbmediald")
minipg.ToUser = "abcd1234abcd1234abcd1234"
minipg.MsgType = "video"
minipg.CustomService.KfAccount = "zhangsan@test"
re,err := kf.SendMsgByKf(minipg)
//config配置文件省略...
wc := wechat.NewWechat(config)
kf := wc.GetCustom()
//创建会话
re, err := kf.CreateKfSession("zhangsan@test","abcd1234abcd1234abcd1234")
//关闭会话
re, err := kf.CloseKfSession("zhangsan@test","abcd1234abcd1234abcd1234")
//获取客户会话状态
re, err := kf.GetKfSession("abcd1234abcd1234abcd1234")
//获取客服会话列表
re, err := kf.GetKfSessionList("zhangsan@test")
//获取未接入会话列表
re, err := kf.GetWaitCaseList() //config配置文件省略...
wc := wechat.NewWechat(config)
kf := wc.GetCustom()
//获取聊天记录 方法返回对应结构体
参数: 开始时间，结束时间，信息id, 数量
re, err := kf.GetMsgList("2018-11-16 00:10:00","2018-11-16 23:10:00",1,1000)
//说明：
//时间格式 2018-11-16 00:10:00，每次查询时段不能超过24小时
//信息id,第一次从1开始，如果一次没获取完，下次输入接口返回的msgid，为下次起始id
//数量：每次获取条数，最多10000条
//返回字段说明
{
"recordlist" : [
{
"openid" : "oDF3iY9WMaswOPWjCIp_f3Bnpljk" ,
"opercode" : 2002,
"text" : " 您好，客服test1为您服务。" ,
"time" : 1400563710,
"worker" : "test1@test"
},
{
"openid" : "oDF3iY9WMaswOPWjCIp_f3Bnpljk" ,
"opercode" : 2003,
"text" : "你好，有什么事情？" ,
"time" : 1400563731,
"worker" : "test1@test"
}
],
"number":2,
"msgid":20165267
}详细Demo：examples/example/custom.go