You may notice that `tests/addons/sinon.js` is committed.
Here is why: 
* Both `npm` and `bower` versions are not suitable. The `npm` version is outdated. The `bower` version is out of sync. (Filed an issue https://github.com/cjohansen/Sinon.JS/issues/359)
* The current version seems to have a bug running in node.js, `ProgressEvent` is not defined, should probably send a pull request to Sinon.JS for that.