Bump cryptography from 3.1 to 3.1.1

Bumps [cryptography](https://github.com/pyca/cryptography) from 3.1 to 3.1.1.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst)
- [Commits](pyca/cryptography@3.1...3.1.1)

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

requirements-pinned.txt

@@ -27,7 +27,7 @@
 attrs==20.2.0
 cffi==1.14.3              # via cryptography, pynacl
 colorama==0.4.3           # via securesystemslib
-cryptography==3.1         # via securesystemslib
+cryptography==3.1.1         # via securesystemslib
 enum34==1.1.10             # via cryptography
 ipaddress==1.0.23         # via cryptography
 iso8601==0.1.13