fix table of contents class name

src/plugins/bookPlayer/plugin.js

@@ -7,7 +7,7 @@ import 'css!./style';
 import 'material-icons';
 import 'paper-icon-button-light';
 
-import TableOfContent from './tableOfContent';
+import TableOfContents from './tableOfContents';
 
 export class BookPlayer {
     constructor() {
@@ -163,7 +163,7 @@ export class BookPlayer {
 
     openTableOfContents() {
         if (this._loaded) {
-            this._tocElement = new TableOfContent(this);
+            this._tocElement = new TableOfContents(this);
         }
     }
 
@@ -271,6 +271,7 @@ export class BookPlayer {
         if (item.Path && (item.Path.endsWith('epub'))) {
             return true;
         }
+
         return false;
     }
 }