Mark release date for beta2

Author: Jean85

CHANGELOG.md

@@ -5,6 +5,8 @@ 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]
+
+## 3.0.0-beta2 - 2019-03-22
  - Disable Sentry's ErrorHandler, and report all errors using Symfony's events (#204)
 
 ## 3.0.0-beta1 - 2019-03-06