Repoman entries with the same timestamp, target, result, and log fields overwrite each other.

[p8952]

            package = Package.where(sha1: sha1).first
            unless package.nil?
                package.add_repoman(
                    Repoman.find_or_create(
                        timestamp: timestamp,
                        target: target,
                        result: result,
                        log: log
                    )
                )
            end

If two items in ci-logs/ have the same values for timestamp, target, result, and log fields one will overwrite the other when running rake db:update_repoman

This does not happen to build entries because the log files are always unique for different packages.