Update CHANGELOG.md

Author: GrahamCampbell

CHANGELOG.md

@@ -5,6 +5,12 @@ 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).
 
+## [11.1.0] - UPCOMING
+
+* Added CI schedule variables endpoints
+
+[11.1.0]: https://github.com/GitLabPHP/Client/compare/11.0.0...11.1.0
+
 ## [11.0.0] - 2020-12-22
 
 * Removed models API