Update changelog for v3.1.0

Author: adamtomat

CHANGELOG.md

@@ -0,0 +1,9 @@
+# Change Log
+All notable changes to this project will be documented in this file.
+This project adheres to [Semantic Versioning](http://semver.org/).
+
+## 3.1.0 (2018-03-28)
+- Add support for view models
+
+## 3.0.0 (2018-03-23)
+- Initial release. Starting at v3 to keep inline with Lumberjack theme version