Coding Standards: Fix the remaining issues in /tests.

All PHP files in `/tests` now conform to the PHP coding standards, or have exceptions appropriately marked.

Travis now also runs `phpcs` on the `/tests` directory, any future changes to these files must conform entirely to the WordPress PHP coding standards. 🎉

See #47632.



git-svn-id: https://develop.svn.wordpress.org/trunk@45607 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/feed/rss2.php

@@ -83,6 +83,7 @@ class Tests_Feeds_RSS2 extends WP_UnitTestCase {
 		// Nasty hack! In the future it would better to leverage do_feed( 'rss2' ).
 		global $post;
 		try {
+			// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
 			@require( ABSPATH . 'wp-includes/feed-rss2.php' );
 			$out = ob_get_clean();
 		} catch ( Exception $e ) {