code: function deleteRouteFromDB(req, res) {
    expectJSON(() => {
      return db.get(req.uri)
        .then(oldData => db.del(req.uri).then(() => oldData));
    }, res);
  }
docs: This route deletes from the db, and returns what used to be there.
  
  Assumptions:
  - that there is no extension if they're deleting data.
  
  NOTE: Return the data it used to contain.  This is often used to create queues or messaging on the client-side,
  because clients can guarantee that only one client was allowed to be the last one to fetch a particular item.
  
  @param {object} req
  @param {object} res