Prep for 2.4.0

CHANGELOG.md

@@ -5,6 +5,8 @@ This project adheres to [Semantic Versioning](http://semver.org/)
 The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 ## [Unreleased]
+
+## [2.4.0] - 2018-05-06
 ### Fixed:
 - Automated SSL key & cert generation fails on systems with Python 2.6 or older (@jaredledvina)
 
@@ -95,7 +97,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 First tagged release, starting at 1.0.0 since the project can be considered stable at this point.
 
-[Unreleased]: https://github.com/sensu/sensu-ansible/compare/2.3.0...HEAD
+[Unreleased]: https://github.com/sensu/sensu-ansible/compare/2.4.0...HEAD
+[2.4.0]: https://github.com/sensu/sensu-ansible/compare/2.3.0...2.4.0
 [2.3.0]: https://github.com/sensu/sensu-ansible/compare/2.2.0...2.3.0
 [2.2.0]: https://github.com/sensu/sensu-ansible/compare/2.1.0...2.2.0
 [2.1.0]: https://github.com/sensu/sensu-ansible/compare/2.0.0...2.1.0