remove useless tests that fail in php 7

Author: Tobion

Tests/Extension/Core/Type/ChoiceTypeTest.php

@@ -66,16 +66,6 @@ protected function tearDown()
         $this->objectChoices = null;
     }
 
-    /**
-     * @expectedException \PHPUnit_Framework_Error
-     */
-    public function testChoicesOptionExpectsArray()
-    {
-        $this->factory->create('choice', null, array(
-            'choices' => new \ArrayObject(),
-        ));
-    }
-
     /**
      * @expectedException \Symfony\Component\OptionsResolver\Exception\InvalidOptionsException
      */