added changelog entry

Author: zashraf1985

packages/datafile-manager/CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 Changes that have landed but are not yet released.
 
+### Changed
+- Added support for authenticated datafiles. `NodeDatafileManager` now accepts `datafileAccessToken` to be able to fetch authentication datafiles.
+
 ## [0.5.0] - April 17, 2020
 
 ### Breaking Changes