convert shebang lines: python -> python3
diff --git a/Demo/scripts/script.py b/Demo/scripts/script.py
index b490b17..a815a35 100755
--- a/Demo/scripts/script.py
+++ b/Demo/scripts/script.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 # script.py -- Make typescript of terminal session.
 # Usage: