v4.3.0b1

!!! This version limits graphql-core to <3.3.0a12 to avoid issue #588

Features

• Add extra_args parameter to subscribe() for aiohttp transport (#584)

Fixes

• Fix DeprecationWarning in test_requests_batch online tests (#582)
• Don't fall back to Apollo when not in subprotocols (#586)

Misc

• DOC Use the session in async subs example (#585)