Bump idna from 2.10 to 3.7

Bumps [idna](https://github.com/kjd/idna) from 2.10 to 3.7.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](https://github.com/kjd/idna/compare/v2.10...v3.7)

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

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

requirements.txt

@@ -11,7 +11,7 @@ chardet==4.0.0
 coloredlogs==15.0
 greenlet==1.1.0
 humanfriendly==9.1
-idna==2.10
+idna==3.7
 pytz==2021.1
 six==1.16.0
 tornado==6.3.3