Clarified version requirements of hammer.js (see #296)

README.md

@@ -150,7 +150,9 @@ slow, so when only the non-minified library is needed, one can use the
 
 The folder `dist` contains bundled versions of vis.js for direct use in the browser. These bundles contain the all visualizations and includes external dependencies such as hammer.js and moment.js.
 
-The source code of vis.js consists of commonjs modules, which makes it possible to create custom bundles using tools like [Browserify](http://browserify.org/) or [Webpack](http://webpack.github.io/). This can be bundling just one visualization like the Timeline, or bundling vis.js as part of your own browserified web application. Note that hammer.js v1.0.6 or newer is required.
+The source code of vis.js consists of commonjs modules, which makes it possible to create custom bundles using tools like [Browserify](http://browserify.org/) or [Webpack](http://webpack.github.io/). This can be bundling just one visualization like the Timeline, or bundling vis.js as part of your own browserified web application. 
+
+*Note that hammer.js version 1 is required (v1.0.6-v1.1.3), version 2 is not yet supported.*
 
 #### Example 1: Bundle a single visualization