Announcing Tornado 6.0b1

[Ben Darnell]

The first beta release of Tornado 6.0 is now available. This release completes the transition that began in version 5.0: Support for Python 2 has been dropped and Tornado only supports versions of Python with asyncio and native coroutines. A lot of legacy callback-based interfaces have been removed as well.  Finally, Tornado now includes full mypy-compatible type hints.

Full draft release notes are at https://www.tornadoweb.org/en/latest/releases/v6.0.0.html

You can try the beta with `pip install tornado==6.0b1`. 

The final release of Tornado 6.0 is tentatively scheduled for March 2.

-Ben