SpringBoot 使用feign时报错Service id not legal hostname(xx_sss）
原因是feign不支持下划线"_"，支持"-",改成xx-sss即可
参考：https://github.com/spring-cloud/spring-cloud-netflix/issues/1582
- Does ribbon support those chars like "_" ? (Though hostname should not contain "_" , but I think it's better to support this feature.)
- If not, I think we Spring Cloud should mention it, .
