Updated exceptions

src/Exception/InvalidCredentialsException.php

@@ -0,0 +1,36 @@
+<?php
+/**
+ * OAuth 2.0 Invalid Credentials Exception
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) Alex Bilbie
+ * @license     http://mit-license.org/
+ * @link        https://github.com/thephpleague/oauth2-server
+ */
+
+namespace League\OAuth2\Server\Exception;
+
+/**
+ * Exception class
+ */
+class InvalidCredentialsException extends OAuthException
+{
+    /**
+     * {@inheritdoc}
+     */
+    public $httpStatusCode = 401;
+
+    /**
+     * {@inheritdoc}
+     */
+    public $errorType = 'invalid_credentials';
+
+    /**
+     * {@inheritdoc}
+     */
+    public function __construct($parameter)
+    {
+        parent::__construct('The user credentials were incorrect..');
+    }
+}