bug symfony#19128 Avoid phpunit 5.4 warnings on getMock (2.7+) (iltar)

This PR was merged into the 2.7 branch.

Discussion
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Avoid phpunit 5.4 warnings on getMock (2.7+)

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#19125
| License       | MIT
| Doc PR        | ~

Avoids calling `getMock()` in phpunit 5.4 which will trigger a warning (and thus failing test suite) when used by developers as this TestCase is an extension point.

Commits
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b05014c Avoid phpunit 5.4 warnings on getMock

Author: nicolas-grekas

src/Symfony/Component/Form/Test/TypeTestCase.php

@@ -30,7 +30,7 @@ protected function setUp()
     {
         parent::setUp();
 
-        $this->dispatcher = $this->getMock('Symfony\Component\EventDispatcher\EventDispatcherInterface');
+        $this->dispatcher = $this->getMockBuilder('Symfony\Component\EventDispatcher\EventDispatcherInterface')->getMock();
         $this->builder = new FormBuilder(null, null, $this->dispatcher, $this->factory);
     }