Update CHANGELOG.md

Author: morgante

CHANGELOG.md

@@ -5,6 +5,10 @@ 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]
+### Changed
+- Updated network/subnetwork lookup to use data source (#16)
+
 ## [v0.2.0] - 2018-09-26
 
 ### Added