Update CHANGELOG for 0.11.0. (#127)

Author: Mike Davis

CHANGELOG.md

@@ -4,6 +4,14 @@ 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).
 
+## [0.11.0] - January 17th, 2020
+- Bump to 1.0.0-rc1@d1b332c of the Optimizely go-sdk
+- Improve build tooling
+- Add standard metrics registry
+- Update documentation
+- Return 404 when feature or experiment are not found
+- Update event payloads to include Agent name and version
+
 ## [0.10.0] - January 9th, 2020
 - Rename repo to optimizely/agent and update imports
 - Improve CI builds for Windows and SourceClear