update integration test to account for already rendered windows from config

__tests__/integration/mirador/thumbnail-navigation.test.js

@@ -3,13 +3,6 @@
 describe('Thumbnail navigation', () => {
   beforeAll(async () => {
     await page.goto('http://127.0.0.1:4488/__tests__/integration/mirador/');
-    await expect(page).toClick('#addBtn');
-    await expect(page).toFill('#manifestURL', 'http://localhost:5000/api/019');
-    await expect(page).toClick('#fetchBtn');
-    // TODO: Refactor the app so we get rid of the wait
-    await page.waitFor(1000);
-    await expect(page).toClick('.mirador-manifest-list-item');
-    await page.waitFor(1000);
   });
 
   it('navigates a manifest using thumbnail navigation', async () => {