Changelog updated for version 0.5.0

Author: remorhaz

CHANGELOG.md

@@ -4,6 +4,6 @@ All notable changes to this project will be documented in this file.
 The 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]
+## [0.5.0] - 2019-11-20
 ### Added
 - Implementation totally refactored.