Fixed definition of extensions, and added CommonJS tests to Travis.
diff --git a/js/gulpfile.js b/js/gulpfile.js
index bdc4212..d8f8ef4 100644
--- a/js/gulpfile.js
+++ b/js/gulpfile.js
@@ -88,3 +88,7 @@
     cb(err);
   });
 });
+
+gulp.task('test', ['test_closure', 'test_commonjs'], function(cb) {
+  cb();
+});