Automate DOI creation for public releases

[shippy]

(This is technically an issue for the SVN repository, but that one doesn't have associated issues.)

Synapse.org has a doi REST API (although the endpoint it exposes that's most alike to what we're interacting with is possibly this?). Currently, we're creating the DOI manually, even though (1) the DOI is predictable from the resource location, (2) the API exists.

As best as I can tell, this API endpoint isn't part of synapseclient, so we'd have to curl (or equivalent) our own.

Doing this from the data_release/cookiecutter/public would also require setting the new author list for public releases, which conditionally excludes dr. DeBellis and conditionally includes dr. Goldston for Y6 and beyond.