Explicitly require python2 in python scripts in tools/

Author: Armaël Guéneau

tools/make-both-single-timing-files.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 import sys
 from TimeFileMaker import *
 

tools/make-both-time-files.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 import sys
 from TimeFileMaker import *
 

tools/make-one-time-file.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 import sys
 from TimeFileMaker import *