Fix changelog badge to match style

Author: skuridin

README.md

@@ -12,7 +12,7 @@ It is tiny (2kB) and has no dependencies.
 [![npm downloads](https://img.shields.io/npm/dm/redux.svg?style=flat-square)](https://www.npmjs.com/package/redux)
 [![redux channel on discord](https://img.shields.io/badge/discord-%23redux%20%40%20reactiflux-61dafb.svg?style=flat-square)](https://discord.gg/0ZcbPKXt5bZ6au5t)
 [![#rackt on freenode](https://img.shields.io/badge/irc-%23rackt%20%40%20freenode-61DAFB.svg?style=flat-square)](https://webchat.freenode.net/)
-[![Changelog #187](https://img.shields.io/badge/changelog-%23187-lightgrey.svg)](https://changelog.com/187)
+[![Changelog #187](https://img.shields.io/badge/changelog-%23187-lightgrey.svg?style=flat-square)](https://changelog.com/187)
 
 >**New! Learn Redux from its creator:  
 >[Getting Started with Redux](https://egghead.io/series/getting-started-with-redux) (30 free videos)**