python / typing

Revert last two changes; bump version to 3.7.4.3
This should address issues due to projects including 'typing' in their
requirements.txt file without a version constraint on Python (or
pinning to 3.7.4.1).

Bump version to 3.7.4.2

Bump version to 3.7.4.1 (#670)

Bump version to 3.7.4 (#651)

Bump version to 3.6.6 (#581)

Bump to version 3.6.4, and add some notes about versions

Bump version to 3.6.2 and use setuptools instead of distutils (#453)
Also update metadata to remove compatibility with 3.5+, and add Ivan
to the list of authors.

Release 3.6.1, drop 3.2 support

Bump version to 3.5.3.0 and add 3.6 support.

Bump version to 3.5.2.2.
(That's the first one I successfully uploaded to PyPI.)

Be explicit about files included (so running python? setup.py sdist
produces the same results for python2 and python3).