Updated CHANGELOG with information about Zenodo (#777)

CHANGELOG.md

@@ -4,7 +4,11 @@ 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).
 
-## [0.5.0] - 2019-10-12
+## [0.5.1] - 2019-10-17
+### Added
+- Integration with Zenodo.org (DOI)
+
+## [0.5.0] - 2019-09-12
 ### Added
 - A converter to YOLO format
 - Installation guide