SNOW-27627: added Python 3.6 support to the description

Author: smtakeda

setup.py

@@ -83,6 +83,7 @@
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
 
         'Topic :: Database',
         'Topic :: Software Development',