Bump cryptography from 2.6.1 to 3.2

Bumps [cryptography](https://github.com/pyca/cryptography) from 2.6.1 to 3.2.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst)
- [Commits](pyca/cryptography@2.6.1...3.2)

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

Author: dependabot[bot]

requirements.txt

@@ -5,7 +5,7 @@ certifi==2019.3.9
 cffi==1.12.3
 chardet==3.0.4
 coverage==4.5.3
-cryptography==2.6.1
+cryptography==3.2
 entrypoints==0.3
 flake8==3.7.7
 idna==2.8

setup.py

@@ -36,7 +36,7 @@
         'dev': ['pep8>=1.7.1,<2',
                 'sphinx >= 2.0.1,<3',
                 'sphinxcontrib-apidoc>=0.3.0',
-                'cryptography>=2.6.1,<2.7',
+                'cryptography>=2.6.1,<3.3',
                 ],
         'test': ['coverage>=4.5.3,<5',
                  'flake8>=3.7.7,<4',