Add eslint and fix reported issues

tests/test.util.js

@@ -1,4 +1,4 @@
-var assert = chai.assert;
+/* eslint-disable no-console */
 var expect = chai.expect;
 
 import * as Log from '../core/util/logging.js';
@@ -68,3 +68,4 @@ describe('Utils', function() {
     //                     (we can't really test them against the browsers, except for Gecko
     //                     via PhantomJS, the default test driver)
 });
+/* eslint-enable no-console */