Filter by multiple set support

[anotheredward]

Hi @metaodi ,

We're looking at adding support to the Config object to support an array of sets, in addition to the current string value.

eg:

{
"metadata_prefix": "oai_dc",
"set": ["portal_12", "item_type_3"]
}

Would generate a url like this: https://api.figshare.com/v2/oai?verb=ListRecords&metadataPrefix=oai_dc&set=portal_12&set=item_type_3

This change won't break any existing harvests, but will allow more specific queries.

Any thoughts on this? And would you be happy to merge this change back in once we're done?

Thanks,
Edward