Add python 3.6 classifier to setup.py

Author: rmk135

setup.py

@@ -80,6 +80,7 @@ def run(self):
           'Programming Language :: Python :: 3.3',
           'Programming Language :: Python :: 3.4',
           'Programming Language :: Python :: 3.5',
+          'Programming Language :: Python :: 3.6',
           'Programming Language :: Python :: Implementation :: CPython',
           'Programming Language :: Python :: Implementation :: PyPy',
           'Topic :: Software Development',