Bump pillow from 6.2.2 to 8.2.0 (#376)

Bumps [pillow](https://github.com/python-pillow/Pillow) from 6.2.2 to 8.2.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](python-pillow/Pillow@6.2.2...8.2.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

poetry.lock

@@ -10,7 +10,7 @@ license = "AGPL-3.0"
 python = "^3.7"
 scipy = "^1.6.0"
 numpy = "1.19.5"
-pillow = "^6.2.1"
+pillow = ">=6.2.1,<9.0.0"
 wkw = "1.1.11"
 requests = "^2.22.0"
 cluster_tools = "^1.52"