update 1.0.0-beta4 label in CHANGELOG

Author: philvarner

CHANGELOG.md

@@ -5,7 +5,7 @@ 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).
 
 
-## [Unreleased - v1.0.0-beta4] - TBD
+## [v1.0.0-beta4] - 2020-10-05
 
 ### Added