message: Updated CHANGELOG for 6.1.3 release.
diff: @@ -6,9 +6,12 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
  and this project adheres to [Semantic Versioning](http://semver.org/).
  ## Unreleased
  +<!-- Add new, unreleased items here. -->
  +
  +## 6.1.3 - 2017-08-26
  +
  * Added `sinon` as dependency of `sinon-chai` in web context to suppress the npm installation warning/error of unmet peer dependency, even though `@polymer/sinonjs` fulfills the runtime dependency and `sinon` will be unused.
  * Set `@polymer/test-fixture` back to ^0.0.3 because of dependency install errors related to yarn's "flat".
  -<!-- Add new, unreleased items here. -->
  ## 6.1.2 - 2017-08-22
  