fix(new): use npm rather than cli to fetch template

@svnlto  
Using npm's api we can use the information it gives us about where it installed the package, rather than relying on assumptions (that were obviously false).
As we delete the folder afterwards it doesn't really matter anyways.

If we decide to go that route we should replace `util/npm` in the other modules, but that can wait. Main issue is shipping a working version of hoodie-cli again :shipit: 

*Integration tests passed, if that still counts anything* :wink: