安装的时候，如果报错：
github.com/fecshopsoft/fec-go/helper/ip.go:17: open /www/test/ip/GeoLite2-City_20180327/GeoLite2-City.mmdb: no such file or directory
可以到github下载： https://github.com/fecshop/trace_fecshop/tree/master/services/golang/ip_lib