refactor app directory structure and add tests

tests/node_modules/nightwatch/examples/mocha/github.js

@@ -0,0 +1,24 @@
+describe('Github', function() {
+
+  it('Demo test GitHub', function (client) {
+    client
+      .url('https://github.com/nightwatchjs/nightwatch')
+      .waitForElementVisible('body', 1000)
+      .assert.title('nightwatchjs/nightwatch · GitHub')
+      .assert.visible('.container h1 strong a')
+      .assert.containsText('.container h1 strong a', 'nightwatch', 'Checking project title is set to nightwatch');
+  });
+
+  after(function(client, done) {
+    if (client.sessionId) {
+      client.end(function() {
+        done();
+      });
+    } else {
+      done();
+    }
+  });
+
+});
+
+