Merge pull request #1298 from jperrin/master

update 7 image to work with overlayfs

library/centos

@@ -1,10 +1,10 @@
 # maintainer: The CentOS Project <[email protected]> (@CentOS)
-# Build date 20151215
+# Build date 20151223
 
 # CentOS 7 rolling builds
-latest: git://github.com/CentOS/sig-cloud-instance-images@93117754c2a3de3c91ab563022f592e7940d293a docker
-centos7: git://github.com/CentOS/sig-cloud-instance-images@93117754c2a3de3c91ab563022f592e7940d293a docker
-7: git://github.com/CentOS/sig-cloud-instance-images@93117754c2a3de3c91ab563022f592e7940d293a docker
+latest: git://github.com/CentOS/sig-cloud-instance-images@e72a549845ecce5563d15e600f1e735a71095dcf docker
+centos7: git://github.com/CentOS/sig-cloud-instance-images@e72a549845ecce5563d15e600f1e735a71095dcf docker
+7: git://github.com/CentOS/sig-cloud-instance-images@e72a549845ecce5563d15e600f1e735a71095dcf docker
 
 # CentOS 6 rolling builds
 centos6: git://github.com/CentOS/sig-cloud-instance-images@20732d1bb34a9aba45c1c6f41576ed6bf3d8c619 docker