python3: fixed support version string, makefile update

Makefile

@@ -29,6 +29,7 b' test-only:'
 test-clean:
 	rm -rf coverage.xml htmlcov junit.xml pylint.log result
 	find . -type d -name "__pycache__" -prune -exec rm -rf '{}' ';'
+	find . -type d -name ".pytest_cache" -prune -exec rm -rf '{}' ';'
 	find . -type f \( -iname '.coverage.*' \) -exec rm '{}' ';'
 
 .PHONY: pip-packages

setup.py

@@ -155,7 +155,7 b' setup('
         'Operating System :: OS Independent',
         'Topic :: Software Development :: Version Control',
         'License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)',
-        'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: 3.10',
     ],
     entry_points={
         'paste.app_factory': ['main=vcsserver.http_main:main']