message: Prepare 2.4.0 release.
diff: @@ -5,8 +5,10 @@ All notable changes to this project will be documented in this file.
  The format is based on [Keep a Changelog](http://keepachangelog.com/)
  and this project adheres to [Semantic Versioning](http://semver.org/).
  -## Unreleased
  +<!-- ## Unreleased -->
  <!-- Add new, unreleased changes here. -->
  +
  +## [2.4.0] - 2018-03-19
  * Fix dependency specification for `babel-core`
  * Add `jsTransform` function, factored out of `optimize-streams` module (so that it can be shared with Polyserve).
  * Renamed `jsTransform` option from `compile` to `compileToEs5` to clarify its behavior.
  