convert shebang lines: python -> python3
diff --git a/Demo/curses/repeat.py b/Demo/curses/repeat.py
index 93372c5..570f221 100755
--- a/Demo/curses/repeat.py
+++ b/Demo/curses/repeat.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 """repeat [-i SECONDS] <shell-command>