spin_setup's get_qubit needs more default values

[slavoutich]

@obriente Don't be lazy and provide default for 'photons': photons, 'alpha0', 'kappa', 'chi' and 'high_frequency'. Or at least don't push WIP code to master.

[obriente]

Let's remove this from master for now, it's been WIP for a year now :(. I've been talking with Stephan Phillips from Lieven's group to work out the details but it never came to fruition.