prepare 0.21.4 release

Author: tillsteinbach

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 ## [Unreleased]
 - No unreleased changes so far
 
+## [0.21.4] - 2021-10-19
+### Fixed
+- Fixes return None for elapsed statistics if no statistics are available
+
 ## [0.21.3] - 2021-10-14
 ### Fixed
 - Fixes picture caching
@@ -334,7 +338,8 @@ Minor fix in observer interface
 ## [0.1.0] - 2021-05-26
 Initial release
 
-[unreleased]: https://github.com/tillsteinbach/WeConnect-python/compare/v0.21.3...HEAD
+[unreleased]: https://github.com/tillsteinbach/WeConnect-python/compare/v0.21.4...HEAD
+[0.21.4]: https://github.com/tillsteinbach/WeConnect-python/releases/tag/v0.21.4
 [0.21.3]: https://github.com/tillsteinbach/WeConnect-python/releases/tag/v0.21.3
 [0.21.2]: https://github.com/tillsteinbach/WeConnect-python/releases/tag/v0.21.2
 [0.21.1]: https://github.com/tillsteinbach/WeConnect-python/releases/tag/v0.21.1