convert shebang lines: python -> python3
diff --git a/Tools/scripts/cleanfuture.py b/Tools/scripts/cleanfuture.py
index e6c8c8c..b48ab60 100644
--- a/Tools/scripts/cleanfuture.py
+++ b/Tools/scripts/cleanfuture.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 """cleanfuture [-d][-r][-v] path ...