[Build Python Wheels] New Repository for Building Python Wheels

[Boyuan Zhang]

Hey all,

Now we have beam-wheels <https://github.com/apache/beam-wheels> as a
wrapper repository to build and stage python wheels for each release. In
order to stage all artifacts successfully, it requires apache credentials.
Please take a look at README
<https://github.com/apache/beam-wheels#apache-beam-wheels> to get more info
if you are interested.

Boyuan Zhang