Update CHANGELOG.md

Author: GrahamCampbell

CHANGELOG.md

@@ -5,6 +5,10 @@ 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).
 
+## [10.3.0] - UPCOMING
+
+[10.3.0]: https://github.com/GitLabPHP/Client/compare/10.2.0...10.3.0
+
 ## [10.2.0] - UPCOMING
 
 * Added variable_type to addVariable and updateVariable