Add std test for doctest.
diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py
new file mode 100644
index 0000000..90a55db
--- /dev/null
+++ b/Lib/test/test_doctest.py
@@ -0,0 +1,2 @@
+import doctest
+doctest.testmod(doctest, verbose=1)