message: Update CHANGELOG for 6.1.5 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
  -* Removed reliance on `document.currentScript` in browser.js because IE11 doesn't have it. (Second reference found)
  <!-- Add new, unreleased items here. -->
  +## 6.1.5 - 2017-08-31
  +
  +* Removed reliance on `document.currentScript` in browser.js because IE11 doesn't have it. (Second reference found)
  +
  ## 6.1.4 - 2017-08-31
  * Removed reliance on `document.currentScript` in browser.js because IE11 doesn't have it.
  