feat: add support for python 3.10 (#626)

Closes #623

Author: parthea

setup.py

@@ -92,6 +92,8 @@
  "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",
  "Operating System :: OS Independent",
  "Topic :: Internet",
  ],