Bump attrs from 19.3.0 to 20.2.0 (#5037)
Bump attrs from 19.3.0 to 20.2.0 (#5037)

Bumps [attrs](https://github.com/python-attrs/attrs) from 19.3.0 to 20.2.0.
- [Release notes](https://github.com/python-attrs/attrs/releases)
- [Changelog](https://github.com/python-attrs/attrs/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/python-attrs/attrs/compare/19.3.0...20.2.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
KeepSafe/aiohttp,KeepSafe/aiohttp,KeepSafe/aiohttp