Make the progress bar for uploads consider bytes, not number of files

[rauchg]

This will provide a much nicer experience to the end-user, by seeing progress of larger files

[sreeramjayan]

@rauchg
I may have misunderstood the implementation, but the current implementation of the progress bar does consider the bytes when an upload occurs
https://github.com/zeit/now-cli/blob/10eb83207b9d5e5da157a3624167dbf24f1c758d/src/providers/sh/commands/deploy.js#L711
It increments it with each upload
https://github.com/zeit/now-cli/blob/10eb83207b9d5e5da157a3624167dbf24f1c758d/src/providers/sh/commands/deploy.js#L722

[pranaygp]

Seems like this actually can't be done with fetch (JakeChampion/fetch#89)
Related: node-fetch/node-fetch#21

[pranaygp]

Also related: https://fetch.spec.whatwg.org/#fetch-api

it is currently lacking when it comes to request progression