fix(tabs): add TabHighlight to IONIC_DIRECTIVES

fixes #8294

Author: manucorporat

src/components/tabs/test/basic/app-module.ts

@@ -273,7 +273,9 @@ export class E2EApp {
     TabsPage
   ],
   imports: [
-    IonicModule.forRoot(E2EApp)
+    IonicModule.forRoot(E2EApp, {
+      tabsHighlight: true,
+    })
   ],
   bootstrap: [IonicApp],
   entryComponents: [

src/directives.ts

@@ -51,6 +51,7 @@ import { Spinner } from './components/spinner/spinner';
 import { Tab } from './components/tabs/tab';
 import { Tabs } from './components/tabs/tabs';
 import { TabButton } from './components/tabs/tab-button';
+import { TabHighlight } from './components/tabs/tab-highlight';
 import { TextInput, TextArea } from './components/input/input';
 import { Thumbnail } from './components/thumbnail/thumbnail';
 import { Toggle } from './components/toggle/toggle';
@@ -228,6 +229,7 @@ export const IONIC_DIRECTIVES: any[] = [
   Tab,
   Tabs,
   TabButton,
+  TabHighlight,
   TextArea,
   TextInput,
   Thumbnail,