minor #17872 [CS] PHPUnit dedicate assert fixer acceptance test (SpacePossum)

This PR was merged into the 2.3 branch.

Discussion
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[CS] PHPUnit dedicate assert fixer acceptance test

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | no
| License       | MIT

The goal of this PR is _not_ to have it merge, but to check with SF community if a new Fixer (PHP-CS-Fixer/PHP-CS-Fixer#1792) should be added to the set of Symfony fixers (at PHP-CS-Fixer).

Commits
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fb141f2 PhpUnitNoDedicateAssertFixer results

Author: fabpot

Tests/Shell/CommandTest.php

@@ -146,7 +146,7 @@ public function testExecute()
         $cmd->add('--version');
         $result = $cmd->execute();
 
-        $this->assertTrue(is_array($result));
+        $this->assertInternalType('array', $result);
         $this->assertNotEmpty($result);
         $this->assertRegexp('/PHP|HipHop/', $result[0]);
     }