Added API docs for #2008

lib/model.js

@@ -816,6 +816,7 @@ module.exports = (function() {
    * @param {String}          aggregateFunction The function to use for aggregation, e.g. sum, max etc.
    * @param {Object}          [options] Query options. See sequelize.query for full options
    * @param {DataType|String} [options.dataType] The type of the result. If `field` is a field in this Model, the default will be the type of that field, otherwise defaults to float.
+   * @param {boolean}         [options.distinct] Applies DISTINCT to the field being aggregated over
    *
    * @return {Promise<options.dataType>}
    */