Add changelog. (#142)

Author: martinmr

CHANGELOG.md

@@ -0,0 +1,38 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project will adhere to [Semantic Versioning](http://semver.org/spec/v2.0.0.html) starting v1.0.0.
+
+## Unreleased
+
+### Changed
+
+### Added
+
+### Fixed
+
+## [0.0.2] - 2020-02-24
+
+[0.0.2]: https://github.com/dgraph-io/ristretto/compare/v0.0.1..v0.0.2
+
+### Added
+
+- Sets with TTL. ([#122][])
+
+### Fixed
+
+- Fix the way metrics are handled for deletions. ([#111][])
+- Support nil `*Cache` values in `Clear` and `Close`. ([#119][]) 
+- Delete item immediately. ([#113][])
+- Remove key from policy after TTL eviction. ([#130][])
+
+[#111]: https://github.com/dgraph-io/ristretto/issues/111
+[#113]: https://github.com/dgraph-io/ristretto/issues/113
+[#119]: https://github.com/dgraph-io/ristretto/issues/119
+[#122]: https://github.com/dgraph-io/ristretto/issues/122
+[#130]: https://github.com/dgraph-io/ristretto/issues/130
+
+## 0.0.1
+
+First release. Basic cache functionality based on a LFU policy.