facebook/react — pull request #2419 by johnheroy (2014-10-28 22:24:20+00:00)
Title: Add comma for readability in tutorial.md

Added comma after dependent clause.

![react pull request](https://cloud.githubusercontent.com/assets/5909572/4818242/141fa672-5ef1-11e4-8d12-970ae136908d.png)