message: Prepare for alpha 25 of the analyzer.
diff: @@ -6,13 +6,16 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
  and this project adheres to [Semantic Versioning](http://semver.org/).
  -## Unreleased
  -
  <!--
  - PRs should document their user-visible changes (if any) below
  - this comment.
  + PRs should document their user-visible changes (if any) in the
  + Unreleased section, uncommenting the header as necessary.
  -->
  +<!--## Unreleased-->
  +
  +
  +## [2.0.0-alpha.25] - 2017-02-22
  +
  ### Added
  * Polymer 2.0 mixin scanner
  * [polymer] Parse polymer databinding expressions.
  