Auto-update zenodo

[mhvk]

@eteq - I see that on zenodo this is still at 1.4. Would be good to auto-update it! Unfortunately, I think you'll have to adjust the settings for that...

[mhvk]

@astrofrog - I see you are an owner too and I think you're the one who initially told me how to auto-link to Zenodo. Could you add that here? Would be good to have that in-place for paper III, so we can cite an up-to-date zenodo link.