5d5f47f manifest: Use mutate-os-release

Authored and Committed by Colin Walters 7 years ago
    manifest: Use mutate-os-release
    
    We now inject the ostree version into /etc/os-release.
    https://trello.com/c/cBzT7tSP/392-2-make-use-of-the-new-mutate-os-release-option-for-rhel-ah