Deletes an aggregator feed.
\Drupal\aggregator\Plugin\Core\Entity\Feed $feed: Feed object representing the feed.
function deleteFeed(Feed $feed) {
$this
->drupalPost('admin/config/services/aggregator/delete/feed/' . $feed
->id(), array(), t('Delete'));
$this
->assertRaw(t('The feed %title has been deleted.', array(
'%title' => $feed
->label(),
)), 'Feed deleted successfully.');
}