added check for angstroms
added check for angstroms

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