Global navigation

@lorenzotello I agree with you about the have_content is better than the be_truthy or be_sublinks, it was my first implementation before I changed. But my main concern was that the application code needs to lose a little idiomatic for the test becomes readable. I think the **both** needs to becomes more idiomatic and readable.

And I think that the has/have is good when you're building matchers, objects to use in the matchers (like capybara plays with have_content and even the api_matchers with have_node), but I think that not fits, this case specifically.

That said, I prefer the code be: **menu_links.sublinks?** instead **menu_links.has_sublinks**.