Fix changelog version

Author: Riimu

CHANGELOG.md

@@ -28,6 +28,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
 - Initial development release
 
-[Unreleased]: https://github.com/simply-framework/application/compare/v0.2.0...HEAD
+[Unreleased]: https://github.com/simply-framework/application/compare/v0.2.1...HEAD
 [0.2.1]: https://github.com/simply-framework/application/compare/v0.2.0...v0.2.1
 [0.2.0]: https://github.com/simply-framework/application/compare/v0.1.0...v0.2.0