chore: update changelog for 18.2.1

Author: jamescdavis

CHANGELOG.md

@@ -4,6 +4,17 @@ 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).
 
+## [18.2.1] - 2018-12-06
+### Added
+- Mirage:
+    - `queryParamIsTruthy` util
+
+### Changed
+- Routes:
+    - `guid-node.registrations` - add `?filter[active]=true` when fetching registration schemas
+- Mirage:
+    - use `queryParamIsTruthy` helper for boolean comparison
+
 ## [18.2.0] - 2018-11-29
 ### Changed
 - Components: