Create v1.6.0 release (#452)

Author: kcajmagic

CHANGELOG.md

@@ -5,6 +5,8 @@ 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]
+
+## [v1.6.0]
 - Added session-id to device information [#451](https://github.com/xmidt-org/webpa-common/pull/451)
 - Added device metadata to outbound events [#451](https://github.com/xmidt-org/webpa-common/pull/451)
 
@@ -53,7 +55,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
  - The first official release. We will be better about documenting changes 
    moving forward.
 
-[Unreleased]: https://github.com/xmidt-org/webpa-common/compare/v1.5.0...HEAD
+[Unreleased]: https://github.com/xmidt-org/webpa-common/compare/v1.6.0...HEAD
+[v1.6.0]: https://github.com/xmidt-org/webpa-common/compare/v1.5.1...v1.6.0
 [v1.5.1]: https://github.com/xmidt-org/webpa-common/compare/v1.5.0...v1.5.1
 [v1.5.0]: https://github.com/xmidt-org/webpa-common/compare/v1.4.0...v1.5.0
 [v1.4.0]: https://github.com/xmidt-org/webpa-common/compare/v1.3.2...v1.4.0