chore(dependencies): Bump cryptography from 2.1.3 to 2.1.4

Bumps [cryptography](https://github.com/pyca/cryptography) from 2.1.3 to 2.1.4.
- [Changelog](https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pyca/cryptography/compare/2.1.3...2.1.4)

requirements.txt

@@ -1 +1 @@
-cryptography==2.1.3
+cryptography==2.1.4

setup.py

@@ -35,6 +35,6 @@ setup(
     ],
     keywords='cryptography noiseprotocol noise security',
     packages=find_packages(exclude=['contrib', 'docs', 'tests', 'examples']),
-    install_requires=['cryptography==2.1.3'],
+    install_requires=['cryptography==2.1.4'],
     python_requires='~=3.5,~=3.6',
 )