Bump pytype from 2020.9.16 to 2020.9.24 (#235)

Bumps [pytype](https://github.com/google/pytype) from 2020.9.16 to 2020.9.24.
- [Release notes](https://github.com/google/pytype/releases)
- [Changelog](https://github.com/google/pytype/blob/master/CHANGELOG)
- [Commits](google/pytype@2020.09.16...2020.09.24)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

setup.py

@@ -25,7 +25,7 @@ def readme():
             "black==20.8b1",
             "flake8>=3.7.9,<3.9.0",
             "isort==5.5.3",
-            "pytype==2020.9.16",
+            "pytype==2020.9.24",
             "pytest>=4.3.1",
             "pytest-cov>=2.6.1",
             "pytest-mock>=3.1.1",