added array type hinting to decode method (#101)

Author: hywak

src/JWT.php

@@ -66,16 +66,13 @@ class JWT
      * @uses jsonDecode
      * @uses urlsafeB64Decode
      */
-    public static function decode($jwt, $key, $allowed_algs = array())
+    public static function decode($jwt, $key, array $allowed_algs = array())
     {
         $timestamp = is_null(static::$timestamp) ? time() : static::$timestamp;
 
         if (empty($key)) {
             throw new InvalidArgumentException('Key may not be empty');
         }
-        if (!is_array($allowed_algs)) {
-            throw new InvalidArgumentException('Algorithm not allowed');
-        }
         $tks = explode('.', $jwt);
         if (count($tks) != 3) {
             throw new UnexpectedValueException('Wrong number of segments');