Bump pillow from 7.1.2 to 8.3.2

Bumps [pillow](https://github.com/python-pillow/Pillow) from 7.1.2 to 8.3.2.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](python-pillow/Pillow@7.1.2...8.3.2)

---
updated-dependencies:
- dependency-name: pillow
  dependency-type: direct:production
...

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Author: dependabot[bot]

requirements.txt

@@ -7,7 +7,7 @@ networkx==2.4
 notebook
 numpy==1.18.1
 pandas==1.0.3
-Pillow==7.1.2
+Pillow==8.3.2
 python-Levenshtein==0.12.2
 PyYaml==5.4
 scikit-image==0.18.1