Add Python 3.5 classifier

setup.py

@@ -60,6 +60,7 @@ CLASSIFIERS = [
     "Programming Language :: Python :: 3.2",
     "Programming Language :: Python :: 3.3",
     "Programming Language :: Python :: 3.4",
+    "Programming Language :: Python :: 3.5",
 ]
 
 version_txt = os.path.join(here, 'supervisor/version.txt')