add python 3.6 classifier to setuptools and pypi

Author: wk

setup.py

@@ -27,6 +27,7 @@
     'Programming Language :: Python :: 3.3',
     'Programming Language :: Python :: 3.4',
     'Programming Language :: Python :: 3.5',
+    'Programming Language :: Python :: 3.6',
     'Operating System :: POSIX :: Linux',
     'Intended Audience :: Developers',
     'Topic :: Software Development :: Libraries',