Upload API

Hi there,

I'd love to see a cli "upload api", which would allow us to 

- upload new mbtiles

- upload mbtiles to existing datasets (to update them)

- ability to delete/remove existing tilesets from the cli as well

- ensuring that any caches (on the CDN and internal servers) get invalidated as soon as a new tileset is uploaded

- ideally having the upload go to a cdn endpoint as well (eg such that the upload is fast relative to where it's coming from, which in our case would be from aws s3)

I understand you might be looking in to this already, and would happily volunteer to beta test it as soon as it's ready.