Updated changelog.

Author: sandeep-ps

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/).
 
+## Unreleased
+
+### Added
+- Docker compose file for starting up the Clowder stack [BD-2226](https://opensource.ncsa.illinois.edu/jira/browse/BD-2226)
+
 ## 2.1.1 - 2018-07-12
 
 ### Fixed