url.parse usage in tilelive.load is unpredicable on windows (remove?)

[springmeyer]

The fallback to url.parse at https://github.com/mapbox/tilelive.js/blob/master/lib/tilelive.js#L81 fails hard on windows. Possible to consider removing this and requiring both protocol and pathname to be defined in a uri object?

At least on windows not passing uri as an object, but rather as a string leads to invalid and unpredicatable pathname results:

[rowanwins]

Gday @springmeyer

I was having some issues with this on windows and was able to resolve this for my case using the filepath module so that might be worth some investigation. If you think it looks promising I'm happy to do a bit more investigation and potentially put together the code properly into a pull request.

Cheers
Rowan