Merge branch '5.1' into 5.2

* 5.1:
  Use createMock() and use import instead of FQCN

Author: nicolas-grekas

Tests/AbstractBrowserTest.php

@@ -14,6 +14,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\BrowserKit\CookieJar;
 use Symfony\Component\BrowserKit\History;
+use Symfony\Component\BrowserKit\Request;
 use Symfony\Component\BrowserKit\Response;
 
 class AbstractBrowserTest extends TestCase
@@ -826,7 +827,7 @@ public function testInternalRequest()
             'NEW_SERVER_KEY' => 'new-server-key-value',
         ]);
 
-        $this->assertInstanceOf(\Symfony\Component\BrowserKit\Request::class, $client->getInternalRequest());
+        $this->assertInstanceOf(Request::class, $client->getInternalRequest());
     }
 
     public function testInternalRequestNull()