upgrade link

Author: guybedford

README.md

@@ -1,5 +1,7 @@
 # ES6 Module Loader Polyfill [![Build Status][travis-image]][travis-url]
 
+_For upgrading to ES6 Module Loader 0.16, [read the release notes here](https://github.com/ModuleLoader/es6-module-loader/releases/tag/v0.16.0)._
+
 Dynamically loads ES6 modules in browsers and [NodeJS](#nodejs-use) with support for loading existing and custom module formats through loader hooks.
 
 This project implements dynamic module loading through `System` exactly to the previous ES6-specified loader API at [2014-08-24 ES6 Specification Draft Rev 27, Section 15](http://wiki.ecmascript.org/doku.php?id=harmony:specification_drafts#august_24_2014_draft_rev_27) and is being converted to track the newly redrafted specification at https://github.com/whatwg/loader (work in progress at https://github.com/ModuleLoader/es6-module-loader/pull/317).