Update CHANGELOG

Author: SammyK

CHANGELOG.md

@@ -7,6 +7,8 @@ Starting with version 5, the Facebook PHP SDK follows [SemVer](http://semver.org
 
 Version 5 of the Facebook PHP SDK is a complete refactor of version 4. It comes loaded with lots of new features and a friendlier API.
 
+- 5.4.3 (2016-12-30)
+  - Fixed a bug that would throw a type error in `GraphEdge` in some cases (#715)
 - 5.4.2 (2016-11-15)
   - Added check for [PHP 7 CSPRNG](http://php.net/manual/en/function.random-bytes.php) first to keep mcrypt deprecation messages from appearing in PHP 7.1 (#692)
 - 5.4.1 (2016-10-18)