Mention Python 3.6 and 3.7 in setup.py.

Author: jonathanslenders

setup.py

@@ -47,6 +47,8 @@ def get_version(package):
  'Programming Language :: Python :: 3.3',
  'Programming Language :: Python :: 3.4',
  'Programming Language :: Python :: 3.5',
+ 'Programming Language :: Python :: 3.6',
+ 'Programming Language :: Python :: 3.7',
  'Programming Language :: Python',
  'Topic :: Software Development',
  ],