Update classifiers

setup.py

@@ -89,13 +89,10 @@ setup_args = dict(
         'License :: OSI Approved :: BSD License',
         'Topic :: Multimedia :: Graphics',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        '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',
         'Framework :: Jupyter',
     ],
     include_package_data = True,