File _servicedata of Package ignition

<servicedata>
  <service name="tar_scm">
    <param name="url">git://github.com/coreos/ignition.git</param>
    <param name="changesrevision">c10c5d4ed00ea05d42223e2877d8f9bdb9f1ce49</param>
 </service>
</servicedata>