Merge pull request #46 from CentOS/master

add official centos distribution image

library/centos

@@ -0,0 +1,4 @@
+# maintainer: The CentOS Project <[email protected]> (@CentOS)
+
+latest: git://github.com/CentOS/sig-cloud-instance-images@feaf968bb0ecdac8f3a5975a95b474818f78e8fd docker
+centos6: git://github.com/CentOS/sig-cloud-instance-images@feaf968bb0ecdac8f3a5975a95b474818f78e8fd docker