Fix tests comma-dangle eslint rule [MAILPOET-1028]

tests/javascript/newsletter_editor/components/heading.spec.js

@@ -8,10 +8,10 @@ define([
       var view;
       beforeEach(function() {
         var model = new Backbone.SuperModel({
-          subject: 'a test subject',
+          subject: 'a test subject'
         });
         view = new (HeadingComponent.HeadingView)({
-          model: model,
+          model: model
         });
       });
 
@@ -24,10 +24,10 @@ define([
         beforeEach(function() {
           model = new Backbone.SuperModel({
             subject: 'a test subject',
-            preheader: 'a test preheader',
+            preheader: 'a test preheader'
           });
           view = new (HeadingComponent.HeadingView)({
-            model: model,
+            model: model
           });
           view.render();
         });