Given GO ids and the obo_dag, create a plot of paths from GO ids.

def plot_gos(fout_png, goids, obo_dag, *args, **kws):
    """Given GO ids and the obo_dag, create a plot of paths from GO ids."""
    engine = kws['engine'] if 'engine' in kws else 'pydot'
    godagsmall = OboToGoDagSmall(goids=goids, obodag=obo_dag).godag
    godagplot = GODagSmallPlot(godagsmall, *args, **kws)
    godagplot.plt(fout_png, engine)