updated SpectralCube.py
updated SpectralCube.py

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