smoothing should respect the downsample keyword
smoothing should respect the downsample keyword

bsipocz/pyspeckit,allisony/pyspeckit,dinossimpson/pyspeckit,bsipocz/pyspeckit,pyspeckit/pyspeckit,keflavich/pyspeckit,e-koch/pyspeckit,jpinedaf/pyspeckit,mikelum/pyspeckit,allisony/pyspeckit,jpinedaf/pyspeckit,vlas-sokolov/pyspeckit,low-sky/pyspeckit,vlas-sokolov/pyspeckit,e-koch/pyspeckit,keflavich/pyspeckit-obsolete,mikelum/pyspeckit,dinossimpson/pyspeckit,low-sky/pyspeckit,keflavich/pyspeckit,pyspeckit/pyspeckit