Merge pull request reactjs#1537 from 0xflotus/patch-1

fixed renderer

Author: alexkrolick

content/docs/reference-test-renderer.md

@@ -118,7 +118,7 @@ Return an object representing the rendered tree. This tree only contains the pla
 testRenderer.toTree()
 ```
 
-Return an object representing the rendered tree. Unlike `toJSON()`, the representation is more detailed than the one provided by `toJSON()`, and includes the user-written components. You probably don't need this method unless you're writing your own assertion library on top of the test rendererer.
+Return an object representing the rendered tree. Unlike `toJSON()`, the representation is more detailed than the one provided by `toJSON()`, and includes the user-written components. You probably don't need this method unless you're writing your own assertion library on top of the test renderer.
 
 ### `testRenderer.update()`