message: Change let to const
diff: @@ -252,7 +252,7 @@ describe('popover', () => {
  const windowEl = getWindow(fixture.nativeElement);
  - let popoverId = windowEl.getAttribute('id');
  + const popoverId = windowEl.getAttribute('id');
  expect(popoverId.indexOf('ngx-popover-')).toEqual(0);
  expect(fixture.nativeElement.querySelector('#div-container').getAttribute('aria-describedby')).toEqual(popoverId);
  