Running this against a 2.3 installation is failing with solr error

@amercader
I know this example is slightly dated, but it's useful to test the new resource view formats.
I upgraded from a 2.2 to a 2.3 installation ...
I'm using the ckan/ckan-docker implementation and ended up having to copy across the 2.3 schema manually to the solr container ...
Any idea why I'm getting this "multiple values encountered for non multiValued field", when the API is being used to push multiple files at once?

Thanks.

python add_example_datasets.py
Creating "Data viewer examples" package
Creating "Example GEOJSON file" resource
Creating "Example JPG file" resource
Error while creating resource: {"help": "http://127.0.0.1/api/3/action/help_show?name=resource_create", "success": false, "error": {"message": "Unable to add package to search index: Solr returned an error: 400 Bad Request - \n\n4001ERROR: [doc=16243cb72e616125ec9797151b9b1c2c] multiple values encountered for non multiValued field res_name: [Example GEOJSON file, Example JPG file]400\n\n", "__type": "Search Index Error"}}

Start with add_example_datasets.py and reproduce the failure using the documented command against the CKAN Docker setup. Then inspect the Solr schema involved in the 2.3 installation and the resource_create request. Done means the example creates multiple file resources without the non-multiValued res_name error.

Written by the indexing model from the issue text.