When asserting if something is downloadable, check if it's in the datastore
When asserting if something is downloadable, check if it's in the datastore

I'm still not convinced that using the format as part of this is correct and
I'm sure there are edge cases that fail for it, but this at least gets over
the non-downloadability of resources when they are posted directly to the
portal using the API.

NaturalHistoryMuseum/ckanext-nhm,NaturalHistoryMuseum/ckanext-nhm,NaturalHistoryMuseum/ckanext-nhm