Revert "Add React Riot hackathon (#9861)"

This reverts commit 3daabf1.

Author: nhunzaker

docs/community/conferences.md

@@ -9,11 +9,6 @@ redirect_from: "docs/conferences.html"
 
 ## Upcoming Conferences
 
-### React Riot 2017
-June 24-25 in Anywhere, Worldwide
-
-[Website](https://www.reactriot.com) - [Twitter](https://twitter.com/reactriot)
-
 ### Chain React 2017
 July 10-11 in Portland, Oregon USA