fix supported python versions list

Author: irmen

setup.cfg

@@ -13,10 +13,10 @@ classifiers =
     License :: OSI Approved :: MIT License
     Programming Language :: C
     Programming Language :: Python
-    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 :: Multimedia :: Sound/Audio
     Topic :: Multimedia :: Sound/Audio :: Conversion
     Topic :: Multimedia :: Sound/Audio :: Capture/Recording