Test calendar.monthrange.

Closes issue 9342. Thanks John Chandler for the patch.
diff --git a/Misc/ACKS b/Misc/ACKS
index 44b8136..f890ee9 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -129,6 +129,7 @@
 Per Cederqvist
 Octavian Cerna
 Pascal Chambon
+John Chandler
 Hye-Shik Chang
 Jeffrey Chang
 Mitch Chapman