message: Updated changelog for 2.0.0-pre4 release.
diff: @@ -5,8 +5,7 @@ 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
  -
  +## 2.0.0-pre.4 - 2017-02-03
  - Fixed a bug where bundling using generateShellMergeStrategy would result in
  builds missing imports which should have been appended to shell.
  