Move vector tile examples to new service

[tillnagel]

End of January Mapzen, the currently used service will stop providing their API.

[Zactravel]

Gruess Dich Till, Shame considering even in Mapzens blog posts they are giving examples of using Mapzen with Unfolding. What does that mean going fwd for fans of unfolding maps? Cheers Zac

Updated comment, direct from Mapzen suggested alternatives https://mapzen.com/blog/migration/