Add CHANGELOG

Author: bf4

CHANGELOG.md

@@ -10,6 +10,8 @@ Features:
 
 Fixes:
 
+- [#1984](https://github.com/rails-api/active_model_serializers/pull/1984#discussion_r89028206) Fix ActiveModelSerializers::Model#attributes to change when attributes are change (@bf4).
+
 Misc:
 
 ### [v0.10.3 (2016-11-21)](https://github.com/rails-api/active_model_serializers/compare/v0.10.2...v0.10.3)