add Plotly.setPlotConfig to API:

- to extend the default config with the API.

Author: etpinard

src/index.js

@@ -18,6 +18,7 @@ exports.prependTraces = Plotly.prependTraces;
 exports.addTraces = Plotly.addTraces;
 exports.deleteTraces = Plotly.deleteTraces;
 exports.moveTraces = Plotly.moveTraces;
+exports.setPlotConfig = require('./plot_api/set_plot_config');
 
 // unofficial 'beta' plot methods, use at your own risk
 exports.Plots = Plotly.Plots;

src/plot_api/set_plot_config.js

@@ -0,0 +1,14 @@
+'use strict';
+
+var Plotly = require('../plotly');
+
+/**
+ * Extends the plot config
+ *
+ * @param {object} configObj partial plot configuration object
+ *      to extend the current plot configuration.
+ *
+ */
+module.exports = function setPlotConfig(configObj) {
+    return Plotly.Lib.extendFlat(Plotly.defaultConfig, configObj);
+};