Update to use MenuBundle 2.0

[wouterj]

No description provided.

[ElectricMaxxx]

Can't add the "Home" MenuItem anymore we are currently doing it in https://github.com/symfony-cmf/symfony-cmf-website/blob/master/src/AppBundle/Menu/MenuProvider.php#L17 It breaks cause the factory was removed from the PhpcrMenuProvider but is needed to build an MenuItem.
We also loose the MenuItem::moveToFirstPosition() method.

With those information the website will be broken after the next build.

[wouterj]

It won't be, as we don't use MenuBundle 2.0 on the site yet

[wouterj]

Btw, I have a working version locally. I'll create a PR as soon as the redesign is a bit further (should be somewhere this week).