Change example location to src folder for easier testing

src/examples/DoughnutExample.js

@@ -0,0 +1,20 @@
+import DoughnutChart from '../BaseCharts/Doughnut'
+
+export default DoughnutChart.extend({
+  ready () {
+    this.render({
+      labels: ['VueJs', 'EmberJs', 'ReactJs', 'AngularJs'],
+      datasets: [
+        {
+          backgroundColor: [
+            '#41B883',
+            '#E46651',
+            '#00D8FF',
+            '#DD1B16'
+          ],
+          data: [40, 20, 80, 10]
+        }
+      ]
+    })
+  }
+})