converting gulpfile to es6

javascript/gulp-functions/GetChartTypes.js

+/* jshint node:true */
+
+const _ = require('lodash');
+const glob = require('glob');
+
+export function getChartTypes(callback) {
+    glob('*.php', {
+        cwd: '../src/Charts/',
+        nomount: true
+    }, (err, chartTypes) => {
+        _.pullAll(chartTypes, [
+            'Chart.php',
+            'ChartBuilder.php',
+            'ChartFactory.php',
+        ]);
+
+        callback(_.map(chartTypes, chartType => {
+            return chartType.slice(0, -4);
+        }));
+    });
+}