Update the URL of Travis-CI status badge.

This update is necessary because the CI platform was migrated
from travis-ci.org to travis-ci.com.

Back-patch to v1.2.

diff --git a/README.md b/README.md
index 5929ee2..8cfe281 100644 (file)
--- a/README.md
+++ b/README.md
@@ -7,4 +7,4 @@ pg_bigm is released under the [PostgreSQL License](https://opensource.org/licens
 For more information look at [the official pg_bigm web site](https://pgbigm.osdn.jp/index_en.html).
 
 ## Test Status
-[![Build Status](https://travis-ci.org/pgbigm/pg_bigm.svg?branch=master)](https://travis-ci.org/pgbigm/pg_bigm)
+[![Build Status](https://travis-ci.com/pgbigm/pg_bigm.svg?branch=master)](https://travis-ci.com/github/pgbigm/pg_bigm)