make axdict user-specifiable in fit_nh3 wrapper
make axdict user-specifiable in fit_nh3 wrapper
vlas-sokolov/pyspeckit,keflavich/pyspeckit,jpinedaf/pyspeckit,low-sky/pyspeckit,vlas-sokolov/pyspeckit,pyspeckit/pyspeckit,e-koch/pyspeckit,keflavich/pyspeckit,e-koch/pyspeckit,jpinedaf/pyspeckit,pyspeckit/pyspeckit,low-sky/pyspeckit