Use / as the primary delimiter in compound key
Use / as the primary delimiter in compound key

We want to avoid confusion between kebab_case'd model names,
and components of the compound key. If for some reason a dev
wants to parse the compound key (i.e. the Solr key) into parts,
using a different top-level delimiter will ease this process.

art-institute-of-chicago/data-aggregator,art-institute-of-chicago/data-aggregator,art-institute-of-chicago/data-aggregator