added astropy as a mock module
added astropy as a mock module

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