Replace underscore's function by ES6 equivalents

lib/cartodb/models/dataview/aggregation.js

@@ -1,4 +1,3 @@
-var _ = require('underscore');
 var BaseWidget = require('./base');
 var debug = require('debug')('windshaft:widget:aggregation');
 
@@ -153,11 +152,13 @@ const TYPE = 'aggregation';
  }
  */
 function Aggregation(query, options, queries) {
-    if (!_.isString(options.column)) {
+    options = options || {};
+
+    if (typeof options.column !== 'string') {
         throw new Error('Aggregation expects `column` in widget options');
     }
 
-    if (!_.isString(options.aggregation)) {
+    if (typeof options.aggregation !== 'string') {
         throw new Error('Aggregation expects `aggregation` operation in widget options');
     }
 
@@ -166,7 +167,8 @@ function Aggregation(query, options, queries) {
     }
 
     var requiredOptions = VALID_OPERATIONS[options.aggregation];
-    var missingOptions = _.difference(requiredOptions, Object.keys(options));
+    var missingOptions = requiredOptions.filter(requiredOption => !options.hasOwnProperty(requiredOption));
+
     if (missingOptions.length > 0) {
         throw new Error(
             "Aggregation '" + options.aggregation + "' is missing some options: " + missingOptions.join(',')
@@ -315,11 +317,7 @@ Aggregation.prototype.format = function(result) {
         minValue = firstRow.min_val;
         maxValue = firstRow.max_val;
         categoriesCount = firstRow.categories_count;
-
-        result.rows.forEach(function(row) {
-            categories.push(_.omit(row, 'count', 'nulls_count', 'min_val',
-                'max_val', 'categories_count', 'nans_count', 'infinities_count'));
-        });
+        categories = result.rows.map(({ category, value, agg }) => ({ category, value, agg }));
     }
 
     return {