Cut 0.2.0 release (#3)

CHANGELOG.md

@@ -5,6 +5,8 @@ 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).
 
 ## [Unreleased]
+
+## [v0.2.0] - 2019-12-20
 ### Added
 - Multiplicative method, PredictMultiplicative.
 ### Changed
@@ -14,5 +16,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Predict function to use Holt-Winters exponential smoothing to predict future values and smooth existing values.
 
-[Unreleased]: https://github.com/jthomperoo/holtwinters/compare/v0.1.0...HEAD
+[Unreleased]: https://github.com/jthomperoo/holtwinters/compare/v0.2.0...HEAD
+[v0.2.0]: https://github.com/jthomperoo/holtwinters/compare/v0.1.0...v0.2.0
 [v0.1.0]: https://github.com/jthomperoo/holtwinters/releases/tag/v0.1.0