Bump pillow from 6.1.0 to 8.3.2 in /requirements

Bumps [pillow](https://github.com/python-pillow/Pillow) from 6.1.0 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@6.1.0...8.3.2)

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

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

Author: dependabot[bot]

requirements/py2_cdeep3m_reqs.txt

@@ -19,7 +19,7 @@ pandas==0.24.2
 pathlib2==2.3.4
 pexpect==4.7.0
 pickleshare==0.7.5
-Pillow==6.1.0
+Pillow==8.3.2
 prompt-toolkit==1.0.16
 protobuf==3.9.1
 ptyprocess==0.6.0

requirements/py3_cdeep3m_reqs.txt

@@ -13,7 +13,7 @@ nose==1.3.7
 numpy==1.16.3
 opencv-contrib-python==4.1.0.25
 opencv-python==4.1.0.25
-Pillow==6.1.0
+Pillow==8.3.2
 protobuf==3.9.1
 ptyprocess==0.6.0
 Pygments==2.4.2