Add 1.2.1 changelog entries

Author: atimmer

CHANGELOG.md

@@ -4,6 +4,11 @@ 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/).
 
+## 1.2.1
+
+### Removed
+- Remove backwards incompatible changes. These are only backwards incompatible in a WordPress context, but this is the target audience.
+
 ## 1.2.0
 
 ### Added