Merge branch '2.8' into 3.1

* 2.8:
  [TwigBridge] removed deprecations added in Twig 1.27
  PHP CS Fixer: use php_unit_dedicate_assert
  3.0 Upgrade Guide: Added details describing how to pass data to a form through the options resolver
  fixed Filesystem:makePathRelative and added 2 more testcases
  no 304 response if method is not cacheable
  move tags from decorated to decorating service

Author: fabpot

Tests/Functional/ProfilerTest.php

@@ -30,7 +30,7 @@ public function testProfilerIsDisabled($insulate)
         $client->enableProfiler();
         $crawler = $client->request('GET', '/profiler');
         $profile = $client->getProfile();
-        $this->assertTrue(is_object($profile));
+        $this->assertInternalType('object', $profile);
 
         $client->request('GET', '/profiler');
         $this->assertFalse($client->getProfile());