websockets

[tarekziade]

Let's add a full example and some documentation on using websockets inside load tests, since it's supported out of the box by aiohttp

http://aiohttp.readthedocs.io/en/stable/client_quickstart.html#aiohttp-client-websockets

cc @rpappalax @chartjes

[rpappalax]

we could use autopush as an example of a working service to try this on: https://github.com/mozilla-services/ap-loadtester/blob/master/aplt/tests/__init__.py#L70