Update changelog

Author: mikebronner

CHANGELOG.md

@@ -2,6 +2,11 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## [4.0.9] - 28 May 2018
+### Added
+- class-name resolution from Service container, allowing for dependency
+  injection.
+
 ## [4.0.8] - 25 Mar 2018
 ### Added
 - work-around for missing `config_path()` function in Lumen.