convert shebang lines: python -> python3
diff --git a/Demo/scripts/morse.py b/Demo/scripts/morse.py
index 5aacaa1..c2f408f 100755
--- a/Demo/scripts/morse.py
+++ b/Demo/scripts/morse.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 # DAH should be three DOTs.
 # Space between DOTs and DAHs should be one DOT.