chore: add Python 3.9 and 3.10 to Trove classifiers (#262)

updated classifiers

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Fixes #<issue_number_goes_here> 🦕

setup.py

@@ -60,6 +60,8 @@
         "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",
         "Topic :: Internet",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],