Update Changelog in prep for release [ci skip]

CHANGELOG.md

@@ -3,12 +3,16 @@
 This format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## [v0.4.1](https://github.com/markphelps/flipt/releases/tag/v0.4.1) - 2019-05-11
 
 ### Added
 
 * `/debug/pprof` [pprof](https://golang.org/pkg/net/http/pprof/) endpoint for profiling
 
+### Fixed
+
+* Issue in evaluation: [https://github.com/markphelps/flipt/issues/63](https://github.com/markphelps/flipt/issues/63)
+
 ## [v0.4.0](https://github.com/markphelps/flipt/releases/tag/v0.4.0) - 2019-04-06
 
 ### Fixed