Update CHANGELOG

Author: thrawn01

CHANGELOG

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 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).
 
+## [0.9.0] - 2020-10-13
+### Change
+* Fix GUBER_MEMBERLIST_ADVERTISE_PORT value type
+* Fixed race condition and updated tests for limit change
+* Fix limit change not having effect until reset
+
 ## [0.8.0] - 2020-01-04
 ### Added
 * Allow cache users to invalidate a ratelimit after a specific time