Update CHANGELOG.md with 1.8.4 release changes

Author: lukeromanowicz

CHANGELOG.md

@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.8.4] - 2019.04.17
+- Use encrypted token for user authentication - @pkarw
+
 ## [1.8.3] - 2019.03.05
 - Use store id from configuration in `mage2vs import` - @boehsermoe (#179)