Bump cryptography from 2.9.2 to 3.0 (#1847)

Bumps [cryptography](https://github.com/pyca/cryptography) from 2.9.2 to 3.0.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pyca/cryptography/compare/2.9.2...3.0)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -4,7 +4,7 @@ attrs==19.3.0
 cchardet==2.1.6
 colorlog==4.1.0
 cpe==1.2.1
-cryptography==2.9.2
+cryptography==3.0
 docker==4.2.2
 gitpython==3.1.7
 jinja2==2.11.2