Issue #156: Changelog entry for replace role authorization bug

Author: Dave Kichler

CHANGELOG.md

@@ -5,6 +5,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ## [Unreleased]
 
 ### Changed
+- [#156](https://github.com/Kashoo/synctos/issues/156): Fix for an edge case where users assigned a replace role may gain the privilege of removing a document erroneously under certain document definition conditions
 - [#157](https://github.com/Kashoo/synctos/issues/157): Swap in Chai as the assertion library used in specs throughout the project
 
 ## [1.9.3] - 2017-10-23