Remove the dependency on the systemd package
    
    The systemd package and journal logging does not offer a huge benefit over
    over simply logging to standard output and letting systemd drop that into
    the journal. Additionally, it makes greenwave more difficult to install by
    requiring systemd headers to be present. Combine this with the desire to
    deploy greenwave as a container in OpenShift, I'd say it's worth
    dropping the module.
    
    Signed-off-by: Jeremy Cline <jeremy@jcline.org>