Update setuptools to 46.4.0

[pyup-bot]

This PR updates setuptools from 46.3.1 to 46.4.0.

Changelog

46.4.0

-------

* 1753: ``attr:`` now extracts variables through rudimentary examination of the AST,
thereby supporting modules with third-party imports. If examining the AST
fails to find the variable, ``attr:`` falls back to the old behavior of
importing the module. Works on Python 3 only.

Links

• PyPI: https://pypi.org/project/setuptools
• Changelog: https://pyup.io/changelogs/setuptools/
• Repo: https://github.com/pypa/setuptools

[duckinator]

bors r+

[bors]

Build succeeded:

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