feat: add support for python 3.10 (#118)

Author: parthea

setup.py

@@ -81,6 +81,8 @@
         "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",
     ],
     platforms="Posix; MacOS X; Windows",
     packages=packages,