test_multipart.py now uses async/await syntax (#2373)
test_multipart.py now uses async/await syntax (#2373)

* test_classbasedview now uses async/await syntax

* test_client_functional.py now uses async/await syntax

* test_client_functional_oldstyle.py now uses async/await syntax

* reverting test_client_functional_oldstyle to old file

* test_client_proto.py now uses async/await style

* fixed PEP errors mentioned by flake8

* fixed flake8 warning for blank lines that contain whitespace

* fixed import order

* test_client_session.py now uses async/await syntax

* test_client_request.py and test_client_response.py now use async/await syntax

* Update CONTRIBUTORS.txt

* coro to be represtend as coroutine than generator

* test_client_ws.py now uses async/await syntax

* test_client_ws_functional.py now uses async/await syntax

* test_connector.py now uses async/await syntax

* test_formdata.py and test_http_writer.py now use async/await syntax

* test_multipart.py now uses async/await syntax

* changed the remaining yield from statements to await

arthurdarcet/aiohttp,arthurdarcet/aiohttp,rutsky/aiohttp,rutsky/aiohttp,pfreixes/aiohttp,arthurdarcet/aiohttp,playpauseandstop/aiohttp,pfreixes/aiohttp,hellysmile/aiohttp,KeepSafe/aiohttp,rutsky/aiohttp,KeepSafe/aiohttp,hellysmile/aiohttp,KeepSafe/aiohttp