test: BDD / acceptance tests

Implement acceptance testing using codeceptjs and puppeteer.

test/acceptance/Menu_test.js

@@ -0,0 +1,9 @@
+Feature('Menu');
+
+Scenario('check if we find the npm commands to set the registry', (I) => {
+  I.amOnPage('http://localhost:8080');
+  I.waitForElement('#header--button-registryInfo', 5);
+  I.click('#header--button-registryInfo');
+  I.waitForElement('#registryInfo--dialog-container');
+  I.see('npm set registry http://localhost:8080');
+});