Bump mistune from 0.8.1 to 2.0.3 in /scikit-learn/6_sentiment_network

Bumps [mistune](https://github.com/lepture/mistune) from 0.8.1 to 2.0.3.
- [Release notes](https://github.com/lepture/mistune/releases)
- [Changelog](https://github.com/lepture/mistune/blob/master/docs/changes.rst)
- [Commits](lepture/mistune@v0.8.1...v2.0.3)

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

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

Author: dependabot[bot]

scikit-learn/6_sentiment_network/requirements.txt

@@ -16,7 +16,7 @@ jupyter-client==5.0.0
 jupyter-console==5.1.0
 jupyter-core==4.3.0
 MarkupSafe==1.0
-mistune==0.8.1
+mistune==2.0.3
 nbconvert==6.5.1
 nbformat==4.3.0
 notebook==6.4.12