Koenig - Render image title attribute if present

refs #9724
- `<img>` elements can have both `alt ` and `title` attributes, ensure we render both of them

Author: kevinansfield

core/server/lib/mobiledoc/cards/image.js

@@ -23,6 +23,9 @@ module.exports = {
         if (payload.alt) {
             img.setAttribute('alt', payload.alt);
         }
+        if (payload.title) {
+            img.setAttribute('title', payload.title);
+        }
 
         figure.appendChild(img);
 

core/test/unit/lib/mobiledoc/cards/image_spec.js

@@ -45,6 +45,20 @@ describe('Image card', function () {
         serializer.serialize(card.render(opts)).should.eql('<figure class="kg-image-card"><img src="https://www.ghost.org/image.png" class="kg-image" alt="example image"></figure>');
     });
 
+    it('renders an image with title attribute', function () {
+        let opts = {
+            env: {
+                dom: new SimpleDom.Document()
+            },
+            payload: {
+                src: 'https://www.ghost.org/image.png',
+                title: 'example image'
+            }
+        };
+
+        serializer.serialize(card.render(opts)).should.eql('<figure class="kg-image-card"><img src="https://www.ghost.org/image.png" class="kg-image" title="example image"></figure>');
+    });
+
     it('renders nothing with no src', function () {
         let opts = {
             env: {