convert shebang lines: python -> python3
diff --git a/Lib/test/test_popen.py b/Lib/test/test_popen.py
index 24fb846..da0c04e 100644
--- a/Lib/test/test_popen.py
+++ b/Lib/test/test_popen.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 """Basic tests for os.popen()
 
   Particularly useful for platforms that fake popen.