added a new test for frequency switching.  Trying to debug a CLASS issue
added a new test for frequency switching.  Trying to debug a CLASS issue

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