Use the json config for wct (lands #138)

wct.conf.js

@@ -1,13 +0,0 @@
-/*
-Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
-This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
-The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
-The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
-Code distributed by Google as part of the polymer project is also
-subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-*/
-
-module.exports = {
-  root: 'app',
-  suites: ['test']
-};

wct.conf.json

@@ -0,0 +1,3 @@
+{
+  "suites": ["app/test"]
+}