Move Past Confs, add React Conf Brazil 2017 (#9697)

* move past confs, add React Conf Brazil 2017

* move react europe to past confs

* resolve react europe conflicts

* Create conferences.md

community/conferences.md

@@ -30,10 +30,15 @@ September 28-30 in Alicante, Spain
 [Website](http://reactalicante.es) - [Twitter](https://twitter.com/ReactAlicante)
 
 ### ReactJS Day 2017
-October 6th in Verona, Italy
+October 6 in Verona, Italy
 
 [Website](http://2017.reactjsday.it) - [Twitter](https://twitter.com/reactjsday)
 
+### React Conf Brasil 2017
+October 7 in Sao Paulo, Brazil
+
+[Website](http://reactconfbr.com.br) - [Twitter](https://twitter.com/reactconfbr) - [Facebook](https://www.facebook.com/reactconf/)
+
 ### State.js Conference 2017
 October 13 in Stockholm, Sweden