declare Python3 support in wheel and trove

setup.py

@@ -1,9 +1,7 @@
-#! python
+#!/usr/bin/env python
 
 """Setup script for the 'uncompyle6' distribution."""
 
-from distutils.core import setup, Extension
-
 # Get the package information used in setup().
 # from __pkginfo__ import \
 #     author,           author_email,       classifiers,                    \