convert shebang lines: python -> python3
diff --git a/Lib/difflib.py b/Lib/difflib.py
index 264860e..292bba9 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 """
 Module difflib -- helpers for computing deltas between objects.