Case RE-652: If there are duplicate packages in the RPM database,
certain steps during the ELevate process, such as running `yum update`,
will fail, halting the process.

In order to try to rectify this issue, use the distro-provided
`package-cleanup --dupes` command to list inappropriate duplicate
packages, sort packages of common name according to version and release,
and carefully remove all but the penultimate package in each list from
the RPM database.

If YUM is still not able to untangle the remaining packages, users may
restore the unmodified RPM database from the backup create and resolve
the issues manually before continuing the ELevate process.

Changelog: Attempt to resolve duplicate RPMs found prior to upgrade.