Adds a CHANGELOG.

Author: jhedstrom

CHANGELOG.md

@@ -0,0 +1,12 @@
+# Change log
+
+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]
+## 1.0.0 2019-08-22
+* Initial release.
+
+[Unreleased]: https://github.com/drupaltest/queue-runner-trait/compare/v1.0.0...HEAD