convert shebang lines: python -> python3
diff --git a/Demo/curses/rain.py b/Demo/curses/rain.py
index 9d46e6e..7cabb4f 100644
--- a/Demo/curses/rain.py
+++ b/Demo/curses/rain.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # $Id$
 #