update changelog

Author: jspaleta

CHANGELOG.md

@@ -4,6 +4,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This CHANGELOG follows the format listed [here](https://github.com/sensu-plugins/community/blob/master/HOW_WE_CHANGELOG.md).
 
 ## [Unreleased]
+### Fixed
+- Fixing asset build directives.
 
 ## [4.0.0] - 2020-01-09