Replace default backend for RSA to Python implementation provided by rsa

package.

Author: Gasper Zejn

setup.py

@@ -1,7 +1,6 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 import os
-import sys
 import jose
 
 from setuptools import setup
@@ -25,6 +24,7 @@ def get_packages(package):
 extras_require = {
     'cryptography': ['cryptography'],
     'pycrypto': ['pycrypto >=2.6.0, <2.7.0'],
+    'pycryptodome': ['pycryptodome >=3.3.1, <4.0.0'],
 }
 
 
@@ -55,5 +55,5 @@ def get_packages(package):
         'Topic :: Utilities',
     ],
     extras_require=extras_require,
-    install_requires=['six <2.0', 'ecdsa <1.0', 'future <1.0', 'pycryptodome >=3.3.1, <4.0.0']
+    install_requires=['six <2.0', 'ecdsa <1.0', 'rsa', 'future <1.0']
 )