Checking in changes prior to tagging of version v0.5.6.

Changelog diff is:

diff --git a/Changes b/Changes
index 075128a..33e7fee 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,11 @@ Revision history for Perl extension Minilla

 {{$NEXT}}

+v0.5.6 2013-07-07T02:36:17Z
+
+    - Show error message when Minilla can't get version number.
+      (tokuhirom)
+
 v0.5.5 2013-07-03T07:28:22Z

     - Fix the problem about not including the author name in stop words.