setup.py: make executable

It's common form to be able to execute setup.py directly.

BUG=None
TEST=`./setup.py ...` works

Change-Id: I3155eca1016cc87d2c64562c15aff19cbb058860
Reviewed-on: https://chromium-review.googlesource.com/716341
Commit-Ready: Mike Frysinger <[email protected]>
Tested-by: Mike Frysinger <[email protected]>
Reviewed-by: Brian Norris <[email protected]>
diff --git a/setup.py b/setup.py
old mode 100644
new mode 100755
index 47761d6..509114d
--- a/setup.py
+++ b/setup.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python2
 # Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.