Bump idna from 2.9 to 2.10

Bumps [idna](https://github.com/kjd/idna) from 2.9 to 2.10.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v2.9...v2.10)

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

requirements.txt

@@ -10,7 +10,7 @@ cornice==5.0.1
 cornice-swagger==1.0.0
 dockerflow==2020.6.0
 hupper==1.10.2
-idna==2.9
+idna==2.10
 iso8601==0.1.12
 jsonpatch==1.26
 jsonpointer==2.0