folding Persistance\ServerSalt into Data\Filesystem

tst/Vizhash16x16Test.php

@@ -1,5 +1,6 @@
 <?php
 
+use PrivateBin\Data\Filesystem;
 use PrivateBin\Persistence\ServerSalt;
 use PrivateBin\Vizhash16x16;
 
@@ -17,7 +18,7 @@ class Vizhash16x16Test extends PHPUnit_Framework_TestCase
             mkdir($this->_path);
         }
         $this->_file = $this->_path . DIRECTORY_SEPARATOR . 'vizhash.png';
-        ServerSalt::setPath($this->_path);
+        ServerSalt::setStore(Filesystem::getInstance(array('dir' => $this->_path)));
     }
 
     public function tearDown()