Bump idna from 2.6 to 3.7 in /resources

Bumps [idna](https://github.com/kjd/idna) from 2.6 to 3.7.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v2.6...v3.7)

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

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

resources/requirements.txt

@@ -8,7 +8,7 @@ Flask==1.1.2
 Flask-SQLAlchemy==2.2
 google-api-python-client==1.6.3
 httplib2==0.19.0
-idna==2.6
+idna==3.7
 itsdangerous==0.24
 Jinja2==2.11.3
 jmespath==0.9.3