Index initial data set as compact JSON-LD in Elasticsearch

See #10

Crawl local N-Triples created with the Metafacture transformation, create compact JSON-LD with non-compact arrays (Elasticsearch requires consistent value types for a given key), index the result.

Deployed to staging: http://staging.api.lobid.org/oer

Sample query: http://staging.api.lobid.org/oer?q=*&t=http://schema.org/CollegeOrUniversity