Update CHANGELOG.md

Author: chriddyp

CHANGELOG.md

@@ -2,7 +2,7 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
-## [Unreleased]
+## [2.0.9] - 2017-04-26
 ### Added
 - Beta: Added API methods that wrap the API endpoint for managing Dash objects on plot.ly. The API interface is under `plotly.api.v2.dash_apps`