Update available method parameters in readme

Author: zachborboa

README.md

@@ -202,7 +202,7 @@ Curl::setURL($url, $data = array())
 Curl::setUserAgent($user_agent)
 Curl::success($callback)
 Curl::unsetHeader($key)
-Curl::verbose($on = true)
+Curl::verbose($on = true, $output=STDERR)
 Curl::http_build_multi_query($data, $key = null)
 Curl::is_array_assoc($array)
 Curl::is_array_multidim($array)