Merge pull request #165 from erikn69/patch-1

Avoid exception `rtrim() Passing null to parameter #1`

src/Milon/Barcode/DNS2D.php

@@ -406,7 +406,7 @@ protected function checkfile($path) {
     }
 
     public function setStorPath($path) {
-        $this->store_path = rtrim($path, '/' . DIRECTORY_SEPARATOR) . DIRECTORY_SEPARATOR;
+        $this->store_path = rtrim((string) $path, '/' . DIRECTORY_SEPARATOR) . DIRECTORY_SEPARATOR;
         return $this;
     }