Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/composer/installers/src/Composer/Installers/TuskInstaller.php

@@ -0,0 +1,14 @@
+<?php
+    namespace Composer\Installers;
+    /**
+     * Composer installer for 3rd party Tusk utilities
+     * @author Drew Ewing <drew@phenocode.com>
+     */
+    class TuskInstaller extends BaseInstaller
+    {
+        protected $locations = array(
+            'task'    => '.tusk/tasks/{$name}/',
+            'command' => '.tusk/commands/{$name}/',
+            'asset'   => 'assets/tusk/{$name}/',
+        );
+    }