Checking in changes prior to tagging of version 1.20.

Changelog diff is:

diff --git a/Changes b/Changes
index 17b33c3..1288149 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,9 @@
 Revision history for Perl extension Test::TCP

+1.20 2013-03-02T18:30:25
+
+    - bump up version
+
 1.19 2013-02-27T14:02:13

     - Split empty_port() function to Net::EmptyPort