update CHANGELOG for v1.0.3 (#46)

Author: pradeepbhadani

CHANGELOG.md

@@ -3,7 +3,7 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [1.0.3] - 2019-01-30
 
 ### Changed
 - Set `server_yaml` to default content when `graphite_host` is not defined.