BUG: fixes plotting with nullable integers (#32073)
- [x] closes #32073
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

Hello @jeandersonbc! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:





There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2020-03-03 18:33:32 UTC Is this still useful? @jeandersonbc can you update and address comments. @jeandersonbc closing as stale. ping if you want to continue.