Updated CHANGELOG

Author: thijskok

CHANGELOG.md

@@ -4,6 +4,15 @@ 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/).
 
+## [4.0.0] - 2020-12-11
+### Added
+- Added Account actions and deprecated Organization as suggested by the API (breaking change, see README) (thanks [gabrielslau](https://github.com/gabrielslau))
+- Wrappers to manage Contacts Lists and track Events (thanks [ashtokalo](https://github.com/ashtokalo)!)
+
+## [3.0.0] - 2019-07-14
+### Updated
+- TestMonitor rebrand
+
 ## [2.0.0] - 2019-07-14
 ### Updated
 - TestMonitor rebrand