Bump openpyxl from 3.0.0 to 3.0.2 in /graders/python (#1876)
Bump openpyxl from 3.0.0 to 3.0.2 in /graders/python (#1876)

Bumps [openpyxl](https://bitbucket.org/openpyxl/openpyxl) from 3.0.0 to 3.0.2.
- [Commits](https://bitbucket.org/openpyxl/openpyxl/commits)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
mwest1066/PrairieLearn,mwest1066/PrairieLearn,mwest1066/PrairieLearn,mwest1066/PrairieLearn,mwest1066/PrairieLearn