Bump pyopenssl from 17.0.0 to 17.5.0

Bumps [pyopenssl](https://github.com/pyca/pyopenssl) from 17.0.0 to 17.5.0.
- [Release notes](https://github.com/pyca/pyopenssl/releases)
- [Changelog](https://github.com/pyca/pyopenssl/blob/master/CHANGELOG.rst)
- [Commits](pyca/pyopenssl@17.0.0...17.5.0)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -1,7 +1,7 @@
 aniso8601==1.2.0
 Flask==0.12.1
 cryptography==2.1.4
-pyOpenSSL==17.0.0
+pyOpenSSL==17.5.0
 PyYAML==3.12
 six==1.11.0
 Werkzeug==0.16.1