Increased min python version to py36. (#73)

Author: Kevin Hellemun

setup.py

@@ -56,15 +56,11 @@
 
         # Specify the Python versions you support here. In particular, ensure
         # that you indicate whether you support Python 2, Python 3 or both.
-        'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
     ],
 
     # Require Python version equal or more than Python 3.
-    python_requires='>=3',
+    python_requires='>=3.6',
 
     # Keywords related to the project
     keywords='open-banking sepa bunq finance api payment',