Fix delete bug
Add regression test
Checking in changes prior to tagging of version 0.05.

Changelog diff is:

diff --git a/Changes b/Changes
index bde3c4e..c8f80ed 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,10 @@ Revision history for Perl extension Coteng

 {{$NEXT}}

+0.05 2013-12-29T18:15:58Z
+
+    - Fix delete method bug.
+
 0.04 2013-12-29T16:58:01Z

     - Fix bug. don't work bulk_insert