Make check_uuid executable

Check_uuid is a script and not a module. This makes it executable
from CLI.

Change-Id: I1c5b6a79e412471f27bc9779dd821a52ec83c645
diff --git a/tools/check_uuid.py b/tools/check_uuid.py
old mode 100644
new mode 100755
index ebbdc78..34effe4
--- a/tools/check_uuid.py
+++ b/tools/check_uuid.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python
+
 # Copyright 2014 Mirantis, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License"); you may