Merge pull request #459 from sunnysideup/patch-3

PATCH: fix docblock for FIle::find

src/File.php

@@ -298,7 +298,7 @@ public function exists()
      * Find a File object by the given filename.
      *
      * @param string $filename Filename to search for, including any custom parent directories.
-     * @return File
+     * @return File|null
      */
     public static function find($filename)
     {