Unable to upload non-model resources

[ElliottKasoar]

If you attempt to upload metadata not labelled with resource_type: id: model, an error is raised:

schema.SchemaError: Key 'metadata' error:
Key 'resource_type' error:
Key 'id' error:
Or('model') did not validate 'dataset'

Suggested fix

I think we need to expand the Or options to include the full set of valid resource types, which is a relatively long list.

I also wonder if it's worth an option to skip validation, in case the user is confident that the schema is out of date?