Update changelog

Author: mikebronner

CHANGELOG.md

@@ -5,6 +5,9 @@ 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).
 
 ## [0.2.57] - 19 May 2018
+### Added
+- database name to cache keys and tags to help with multi-tenancy use-cases.
+
 ### Fixed
 - `find()` using array parameter.