code: function makeRelations (type, ids, options) {
    var res = []
  
    _.each(ids, function (id) {
      res.push(makeRelation(type, id, options))
    })
  
    return res
  }
docs: Handles a creating a collection of relations.
  @private
  @memberOf {Serializer}
  @param {String} type
  @param {Array} ids
  @param {Object} options
  @return {Array}