convert shebang lines: python -> python3
diff --git a/Demo/pdist/rcvs.py b/Demo/pdist/rcvs.py
index 4e2532a..ff178b7 100755
--- a/Demo/pdist/rcvs.py
+++ b/Demo/pdist/rcvs.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 """Remote CVS -- command line interface"""