Update Changelog for release of version 3.0.3

Author: LaunchDarklyCI

CHANGELOG.md

@@ -3,6 +3,14 @@
 
 All notable changes to the LaunchDarkly Java SDK will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org).
 
+## [3.0.3] - 2018-03-26
+### Fixed
+* In the Redis feature store, fixed a synchronization problem that could cause a feature flag update to be missed if several of them happened in rapid succession.
+* Fixed a bug that would cause a `NullPointerException` when trying to evaluate a flag rule that contained an unknown operator type. This could happen if you started using some recently added feature flag functionality in the LaunchDarkly application but had not yet upgraded the SDK to a version that supports that feature. In this case, it should now simply treat that rule as a non-match.
+
+### Changed
+* The log message "Attempted to update ... with a version that is the same or older" has been downgraded from `WARN` level to `DEBUG`. It can happen frequently in normal operation when the client is in streaming mode, and is not a cause for concern.
+
 ## [3.0.2] - 2018-03-01
 ### Fixed
 - Improved performance when evaluating flags with custom attributes, by avoiding an unnecessary caught exception (thanks, [rbalamohan](https://github.com/launchdarkly/java-client/issues/113)).