feat: add support for python 3.10 (#228)

Author: parthea

setup.py

@@ -58,9 +58,13 @@
         "Development Status :: 5 - Production/Stable",
         "Intended Audience :: Developers",
         "Operating System :: OS Independent",
+        "Programming Language :: Python",
+        "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",
         "Topic :: Internet",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],