bugfix: matplotlib still can't handle units ever.
bugfix: matplotlib still can't handle units ever.

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