Preparing release v0.3.0

This release includes a change to the internal implementation (#100).
No API or behavior changes.

The change was on tip for ~9 months, it should be safe to switch.

CHANGELOG.md

@@ -4,8 +4,10 @@ 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 adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## Unreleased
--  No changes yet.
+## v0.3.0 - 2023-07-08
+### Changed
+- Switched to a more efficient internal implementation. No API or behavior changes.
+  [#100](https://github.com/uber-go/ratelimit/pull/100)
 
 ## v0.2.0 - 2021-03-02
 ### Added