Merge branch '3.4' into 4.3

* 3.4:
  Various tweaks 3.4
  [PhpUnit] Fix usleep mock return value
  [Lock] use Predis\ClientInterface instead of Predis\Client

Author: nicolas-grekas

Tests/Firewall/UsernamePasswordFormAuthenticationListenerTest.php

@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Component\Security\Tests\Http\Firewall;
+namespace Symfony\Component\Security\Http\Tests\Firewall;
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\RedirectResponse;

Tests/Firewall/UsernamePasswordJsonAuthenticationListenerTest.php

@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Component\Security\Tests\Http\Firewall;
+namespace Symfony\Component\Security\Http\Tests\Firewall;
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\Request;