refactor app directory structure and add tests

tests/node_modules/nightwatch/examples/custom-commands/hasOnBeforeUnload.js

@@ -0,0 +1,18 @@
+/**
+ * Simple example of custom command. This command will
+ * check if there's a onbeforeunload handler in the target web page
+ * and return the result
+ */
+/* global window */
+
+module.exports.command = function(callback) {
+  var self = this;
+
+  this.execute(function() {
+    return window && typeof window.onbeforeunload === 'function';
+  }, [], function(result) {
+    callback.call(self, result.value);
+  });
+
+  return this;
+};