Change shebang to python2 (see PEP394)

Would've prevented #7

mumo_manager_test.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 # -*- coding: utf-8
 
 # Copyright (C) 2010 Stefan Hacker <dd0t@users.sourceforge.net>
@@ -181,4 +181,4 @@ class MumoManagerTest(unittest.TestCase):
 
 if __name__ == "__main__":
     #import sys;sys.argv = ['', 'Test.testName']
-    unittest.main()
+    unittest.main()