Update CHANGELOG.md

Author: Chman

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this package will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [2.1.5] - 2019-xx-xx
+## [2.1.5] - 2019-03-25
 
 ### Fixed
 - LDR Color grading in gamma mode no longer produces banding artifacts on Mali GPUs on OpenGL ES2.