1578 make owl api work with ontohub urls that have no filename extension (#1768) * API controller is now invoked when no Accept header is sent * Use text/plain as default for ontology versions api * Send correct accept header * Fix the ref based locid route * Remove ref_id * Remove debug puts * Fix locid routing tests * route html to api * Add routes.rb to ignore list * Move plain text default helper to concern * Fix test * More tests require accept header * Remove tags from steps