diff -up ./setup.py.orig ./setup.py
--- ./setup.py.orig	2017-01-11 00:03:45.000000000 +0100
+++ ./setup.py	2017-01-11 14:08:31.529364574 +0100
@@ -73,7 +73,7 @@ setup(
     install_requires=[
         'PyJWT>=1.0.0',
         'requests>=2.0.0',
-        'python-dateutil>=2.1.0',
+        'python-dateutil',
         'cryptography>=1.1.0'
     ]
 )