Update supported Python versions in setup.py

Author: pont-us

setup.py

@@ -356,5 +356,8 @@ def run(self):
                    # 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 :: 3.4',
+                   'Programming Language :: Python :: 3.5',
+                   'Programming Language :: Python :: 3.6',
+                   'Programming Language :: Python :: 3.7',
                    'Programming Language :: Python :: 3.8'
                    ])