bugfix: if a template model has no docstring, don't try to append it
bugfix: if a template model has no docstring, don't try to append it

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