fix: add json-digger dependency

Close #79

Author: javier-godoy

src/main/java/com/flowingcode/vaadin/addons/orgchart/OrgChart.java

@@ -54,6 +54,7 @@
 @Tag("fc-orgchart")
 @JsModule("./fc-orgchart.js")
 @CssImport("./fc-orgchart-styles.css")
+@NpmPackage(value = "json-digger", version = "2.0.2")
 public class OrgChart extends Div {
 
   private OrgChartItem orgChartItem;

src/main/resources/META-INF/frontend/fc-orgchart.js

@@ -20,6 +20,7 @@
 import {html, PolymerElement} from '@polymer/polymer/polymer-element.js';
 import jQuery from "jquery";
 import html2canvas from 'html2canvas';
+import JSONDigger from "json-digger/dist/json-digger.js";
 
 /**
  * `fc-orgchart`
@@ -93,6 +94,7 @@ class FCOrgChart extends PolymerElement {
         });  
 
         window.html2canvas = html2canvas;
+        window.JSONDigger  = JSONDigger;
 
         // add title
         var title = state.chartTitle;