message: Add [Unreleased] placeholder to changelog
diff: @@ -4,6 +4,8 @@ All notable changes to this project will be documented in this file.
  The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
  and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
  +## [Unreleased]
  +
  ## [0.4.1] - 2018-06-26
  ### Changed
  - Anonymize IPs sent to Google Analytics
  