Updated CHANGELOG

Author: oscarotero

CHANGELOG.md

@@ -5,6 +5,17 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/) 
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## UNRELEASED
+
+### Added
+
+- Improved testing and added code coverage reporting
+- Added tests for PHP 7.2
+
+### Fixed
+
+- Updated license year
+
 ## [0.5.0] - 2017-11-13
 
 ### Changed