Adding optional dependencies to travis, and build without optionals to the matrix
Adding optional dependencies to travis, and build without optionals to the matrix

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