unpin pyjwt

pyjwt is pinned to <2.0, preventing installation of current pyjwt

The current use of pyjwt appears to works just fine on pyjwt 2

Author: minrk

setup.py

@@ -22,7 +22,7 @@ def read(fname):
     packages=find_packages(),
     long_description=read('README.rst'),
     install_requires=[
-        'PyJWT>=1.0.1,<2.0.0',
+        'PyJWT>=1.0.1',
         'oauthlib',
         'requests',
         'requests-oauthlib',