fixed failing test

[svycka]

When running tests locally there was one failing test:

There was 1 failure:

1) ZendTest\Form\View\Helper\FormRowTest::testIgnoreLabelForHidden
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'<input type="hidden" name="foo" value=""/>'
+'<input type="hidden" name="foo" value="">'

/vagrant/projects/zend-form/test/View/Helper/FormRowTest.php:124

[Maks3w]

What php version are you using?

[svycka]

$ php -v
PHP 5.6.13-1+deb.sury.org~trusty+2 (cli)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2015 Zend Technologies
with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2015, by Zend Technologies

[Maks3w]

with append ? plus escape the slash is enough

value=""\/?>

[svycka]

I sow that other tests using this regexp so I used too don't know why they did it like this. But I can change if you think its better