Weird Referer header requirement

[dave-mills]

Found that for my hastily written shareFormWithUser() endpoint, I needed to manually add a Referer header.

No idea why. Also no idea why I needed it there but the customRegisterProject (which I copied the structure from for the new one) doesn't seem to need this header.

Less of a bug to fix and more of a curio, unless we find this same issue with any endpoints that we're actually keeping long-term.

[chrismclarke]

I saw this once and don't know why/where. Would be good to find consistent way to recreate before investigating further (will test on your endpoint, which on first glance looks totally fine).

As an aside, is there a reason to not just do the sharing through projects? Also change 'form_id' to formid in the body json for consistency (#16 which you may have missed) and then feel free to add a pull request/merge in.