Fix of save functionality

app/components/SimpleEditor/SimpleEditor.jsx

@@ -77,7 +77,7 @@ export default class SimpleEditor extends React.Component {
     const exporter = new SimpleExporter(config)
     const convertedSource = exporter.exportDocument(source)
 
-    onSave(convertedSource)
+    return onSave(convertedSource)
   }
 
   // NOTE -- Theoretically, we shouldn't lock when the editor is in read only

app/components/SimpleEditor/SimpleEditorWrapper.jsx

@@ -73,14 +73,13 @@ export class SimpleEditorWrapper extends React.Component {
     const { fragment } = this.props
     fragment.source = source
 
-    this.update(fragment)
-    // return callback()
+    return this.update(fragment)
   }
 
   update (newChapter) {
     const { book } = this.props
     const { updateFragment } = this.props.actions
-    updateFragment(book, newChapter)
+    return updateFragment(book, newChapter)
   }
 }