Update Changelog for release of version 2.3.0

CHANGELOG.md

@@ -2,6 +2,19 @@
 
 All notable changes to the LaunchDarkly Go SDK will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org).
 
+
+## [2.3.0] - 2018-01-31
+
+### Changed
+- When evaluating a feature flag, if the client has not yet fully initialized but you are using a Redis store that has already been populated, the client will now use the last known feature data from Redis rather than returning a default value.
+- In polling mode, the minimum polling interval is now 30 seconds. Smaller configured values will be adjusted up to the minimum.
+- The streaming client will no longer reconnect after detecting an invalidated SDK key.
+- Added a build tag, `launchdarkly_no_redis`, which allows building without the Redis dependency.
+
+### Fixed
+- Fixed a bug where a previously deleted feature flag might be considered still available.
+
+
 ## [2.2.3] - 2017-12-21
 
 ### Added