一定是所在的服务器也装了MongoDB导致端口冲突，解决方法：kill掉全部MongoDB的进程。
ps aux | grep mongod kill -9 PID
参考：
http://blog.csdn.net/guoer9973/article/details/52103367
https://www.cnblogs.com/wjw-blog/p/5995237.html?utm_source=itdadao&utm_medium=referral
https://github.com/jhipster/generator-jhipster/issues/2398
https://github.com/flapdoodle-oss/de.flapdoodle.embed.mongo/issues/176
