Update changelog

src/readme.txt

@@ -160,6 +160,16 @@ You can install PublishPress through your WordPress admin area:
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+= [1.4.0] - 2017-05-25 =
+
+* Fixed:
+* Restores the icon in the freemius sdk
+* Fixed minor JavaScript warning in the Editorial Comment module
+
+* Changed:
+* Refactor notification module allowing add-ons to use any other message system
+* Allow to customize priority for the action triggered on the status change
+
 = [1.3.3] - 2017-05-22 =
 * Fixed:
 * Fixed the context in translations for date picker in the Story Budget module