Update README.md

Author: BookaiCode

README.md

@@ -186,7 +186,7 @@
 - [实战Arthas：常见命令与最佳实践](https://mp.weixin.qq.com/s?__biz=Mzg4Nzc3NjkzOA==&mid=2247488559&idx=1&sn=4b5003cb33446ab4a6173285fe9d83d3&chksm=cf8467eaf8f3eefc033de8f63cba9f0d7b2b5eb0ccfb5209f458a9ab447367b34954f296638b#rd)
 - [Maven实战](https://mp.weixin.qq.com/s/ErtWrRNzjJcR2ettUhAxsQ)
 - [不用Mockito写单元测试？你可能在浪费一半时间](https://mp.weixin.qq.com/s/NICubD9Yq0pn6qwpVIznfg)
-- [用好PowerMock，轻松搞定那些让你头疼的单元测试]()
+- [用好PowerMock，轻松搞定那些让你头疼的单元测试](https://mp.weixin.qq.com/s/rWIjqJKBQOe72RWW6qyJmA)
 
 ###  :bulb: 资源  ###