AlignDoubleArrowFixer - add next test

This code is perfectly valid, but it is changed:
```diff
 <?php
                     $a = array(
-                        0  => 1,
-                        10 => array(
+                        0      => 1,
+                        10     => array(
                             1  => 2,
                             22 => 3,
                         ),
-                        100 => array(
+                        100    => array(
                             1  => 2,
                             22 => 3,
                         )
                     );
```