Update changelog

Author: jkodumal

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes to the LaunchDarkly Ruby SDK will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org).
 
+## [2.0.2] - 2016-08-08
+## Changed
+- The default logger now logs at `info` level
+
 ## [2.0.0] - 2016-08-08
 ### Added
 - Support for multivariate feature flags. In addition to booleans, feature flags can now return numbers, strings, dictionaries, or arrays via the `variation` method.