Hi,

I have trouble performing an authenticated request. I sniffed the traffic with tcpdump and discovered the authorization header is not sent.
I think the auth parameter (https://github.com/KeepSafe/aiohttp/blob/master/aiohttp/client.py#L38) is not used in the request method during the instanciation of the request_class (https://github.com/KeepSafe/aiohttp/blob/master/aiohttp/client.py#L96).

The change seems to have been introduced in 50a95fb.