Webaudio tests

Hi, 

I'm the co-chair of the Web Audio WG, and leading our testing effort for the Web Audio API. We've made a very basic start on some tests for the API, and as I mentioned on the testing mailing list a few weeks ago, could we have them merged in to master please? 

Going forward, I'd like to be able to manage the review of pull requests that get sent against the `webaudio` directory - would you be able to set me up with the appropriate access to do that please?