FIX: Py3k compatibility.

Fixes https://github.com/scikit-learn/scikit-learn/issues/395

setup.py

@@ -55,6 +55,8 @@ if __name__ == "__main__":
             shutil.rmtree(local_path)
         print("Copying source tree into build/py3k for 2to3 transformation"
               "...")
+        shutil.copytree(os.path.join(old_path, 'scikits'),
+                        os.path.join(local_path, 'scikits'))
         shutil.copytree(os.path.join(old_path, 'sklearn'),
                         os.path.join(local_path, 'sklearn'))
         import lib2to3.main