Added Python3 classifiers in setup.py

Author: bmispelon

setup.py

@@ -30,4 +30,16 @@
     ]},
     test_suite='runtests',
     tests_require='lxml',
+    classifiers=[
+        'Programming Language :: Python',
+        'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
+        'Framework :: Trac',
+    ],
 )