Update changelog for release

Author: taion

CHANGES.md

@@ -1,10 +1,15 @@
-## [HEAD]
-> Unreleased
+## [v2.3.0]
+> April 18, 2016
 
-- **Feature:** Added `applyRouterMiddleware` ([#3327])
+- **Feature:** Add `applyRouterMiddleware` for extending router rendering ([#3327])
+- **Feature/Deprecation:** Add `routerShape` and `locationShape` as top-level exported prop types, and deprecate all the old prop types, including the ones that were previously incorrectly removed ([#3349])
+- **Minor:** Move ES module build back to `es6/` to avoid breaking people who were incorrectly importing from `react-router/es6` ([#3334])
 
-[HEAD]: https://github.com/reactjs/react-router/compare/v2.2.4...master
+[v2.3.0]: https://github.com/reactjs/react-router/compare/v2.2.4...v2.3.0
 [#3327]: https://github.com/reactjs/react-router/issues/3327
+[#3334]: https://github.com/reactjs/react-router/issues/3334
+[#3349]: https://github.com/reactjs/react-router/issues/3349
+
 
 ## [v2.2.4]
 > April 15, 2016