Fix release date

Author: Matt Carroll

packages/optimizely-sdk/CHANGELOG.MD

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [2.2.0] - September 25, 2018
+## [2.2.0] - September 26, 2018
 
 ### Fixed
 - Track and activate should not remove null attributes ([#168](https://github.com/optimizely/javascript-sdk/pull/168))