Update changelog, bumping v2.2.1

* Closes #18

CHANGELOG.md

@@ -3,6 +3,12 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/) and [Keep a CHANGELOG](http://keepachangelog.com).
 
+## [2.2.1] - 2018-12-16
+
+### Fixed
+
+* Missing authentication at redis server when `auth` config value was set - [#18]
+
 ## [2.2.0] - 2018-06-27
 
 ### Added
@@ -83,6 +89,7 @@ This project adheres to [Semantic Versioning](http://semver.org/) and [Keep a CH
 
 First stable release.
 
+[2.2.1]: https://github.com/hollodotme/readis/compare/v2.2.0...v2.2.1
 [2.2.0]: https://github.com/hollodotme/readis/compare/v2.1.0...v2.2.0
 [2.1.0]: https://github.com/hollodotme/readis/compare/v2.0.0...v2.1.0
 [2.0.0]: https://github.com/hollodotme/readis/compare/v1.1.3...v2.0.0
@@ -94,4 +101,5 @@ First stable release.
 [1.0.0]: https://github.com/hollodotme/readis/tree/v1.0.0
 
 [issue #8]: https://github.com/hollodotme/readis/issues/8
-[issue #9]: https://github.com/hollodotme/readis/issues/9
+[issue #9]: https://github.com/hollodotme/readis/issues/9
+[issue #18]: https://github.com/hollodotme/readis/issues/18