Fixed reference error after fixup

SamiTwigExtension.php

@@ -772,19 +772,19 @@ class SamiTwigExtension extends \Twig_Extension {
         if (!empty($traits)) {
             foreach($traits as $key => $trait)
                 $traits[$key] = self::render_class($trait);
-            array_unshift($t, "## Traits");
+            array_unshift($traits, "## Traits");
         }   
 
         if (!empty($interfaces)) {
             foreach($interfaces as $key => $interface)
                 $interfaces[$key] = self::render_class($interface);
-            array_unshift($i, "## Interfaces");
+            array_unshift($interfaces, "## Interfaces");
         } 
 
         if (!empty($exceptions)) {
             foreach($exceptions as $key => $exception)
                 $exceptions[$key] = self::render_class($exception);
-            array_unshift($e, "## Exceptions");
+            array_unshift($exceptions, "## Exceptions");
         }
         return sprintf("%s%s%s%s", 
             self::join($classes),