
Yum can process the mirror list in metalink format, which provides additional security checking capability. Yum compares the SHA1 checksums of each repository's repomd.xml file against that of the master mirrors. This ensures that significantly out-of-date mirrors are not used and should reduce our CI timeouts issues. Change-Id: I5beb0de2bca28b12001aaae01b5503d69bfb7727