setup: update pypi classifiers

Author: drsteve

setup.py

@@ -24,10 +24,12 @@
                    'Topic :: Scientific/Engineering :: Atmospheric Science',
                    'Topic :: Scientific/Engineering :: Information Analysis',
                    'Topic :: Scientific/Engineering :: Physics',
-                   'Programming Language :: Python :: 2',
-                   'Programming Language :: Python :: 2.7',
                    'Programming Language :: Python :: 3',
                    'Programming Language :: Python :: 3.6',
+                   'Programming Language :: Python :: 3.7',
+                   'Programming Language :: Python :: 3.8',
+                   'Programming Language :: Python :: 3.9',
+                   'Programming Language :: Python :: 3.10',
                    ],
       test_suite='test_verify.py'
       )