Bump cryptography from 2.7 to 39.0.1

Bumps [cryptography](https://github.com/pyca/cryptography) from 2.7 to 39.0.1.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/main/CHANGELOG.rst)
- [Commits](https://github.com/pyca/cryptography/compare/2.7...39.0.1)

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

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

requirements.txt

@@ -30,7 +30,7 @@ constantly==15.1.0
 coreapi==2.3.3
 coreschema==0.0.4
 croniter==0.3.30
-cryptography==2.7
+cryptography==39.0.1
 daphne==2.3.0
 decorator==4.3.0
 defusedxml==0.6.0