Support RHEL8 - systemd timers

[traylenator]

Just looking to add RHEL 8 support here .

So significantly the RHEL8 mlocate package uses systemd timers.

Happy to do but proceeding with

#24

may make sense.

[traylenator]

@adamcrews I see you are are VoxPupuli member ? How about moving into that framework? Happy to help/do.