Description:
------------
According to the documentation on which can be found at https://wiki.php.net/rfc/void_return_type, the following should be valid:

function returns_nothing(): void {
    return; // valid
}

On our local development-server (PHP 7.1.0-dev (cli) (built: Nov 27 2015 16:10:23) ( NTS ) with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2015, by Zend Technologies) this works as described in the wiki.

We set up a new server in the data-center (PHP 7.0.4-3+deb.sury.org~trusty+4 (cli) ( NTS ) with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies), but when we execute the same code there, it gives a PHP Fatal error:  Uncaught TypeError: Return value of test() must be an instance of void, null returned in test.php:5\nStack trace:\n#0 test.php(8): test()\n#1 {main}\n  thrown in test.php on line 5

Test script:
---------------
<?php

        function test() : void
        {
                return;
        }

        test();

?>

Expected result:
----------------
Function should be valid, return; on a function() : void should be correct and/or documentation should be updated to match the way PHP reacts.