Update setuptools to 50.2.0

[pyup-bot]

This PR updates setuptools from 50.0.0 to 50.2.0.

Changelog

### 50.2.0 ``` ------- * 2355: When pip is imported as part of a build, leave distutils patched. * 2380: There are some setuptools specific changes in the `setuptools.command.bdist_rpm` module that are no longer needed, because they are part of the `bdist_rpm` module in distutils in Python 3.5.0. Therefore, code was removed from `setuptools.command.bdist_rpm`. ``` ### 50.1.0 ``` ------- * 2350: Setuptools reverts using the included distutils by default. Platform maintainers and system integrators and others are *strongly* encouraged to set ``SETUPTOOLS_USE_DISTUTILS=local`` to help identify and work through the reported issues with distutils adoption, mainly to file issues and pull requests with pypa/distutils such that distutils performs as needed across every supported environment. ``` ### 50.0.3 ``` ------- * 2363: Restore link_libpython support on Python 3.7 and earlier (see pypa/distutils9). ``` ### 50.0.2 ``` ------- * 2352: In distutils hack, use absolute import rather than relative to avoid bpo-30876. ``` ### 50.0.1 ``` ------- * 2357: Restored Python 3.5 support in distutils.util for missing `subprocess._optim_args_from_interpreter_flags`. * 2358: Restored AIX support on Python 3.8 and earlier. * 2361: Add Python 3.10 support to _distutils_hack. Get the 'Loader' abstract class from importlib.abc rather than importlib.util.abc (alias removed in Python 3.10). ```

Links

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

[coveralls]

Coverage remained the same at 86.168% when pulling 578a38d5150022dccdc76c8ebdbf9174c265747e on pyup-update-setuptools-50.0.0-to-50.2.0 into a8efce0ad44c9f9135fb1701696a982a9a266c45 on master.

[pyup-bot]

Closing this in favor of #255