Simplify WPT attachment download.
Simplify WPT attachment download.

Promise.join is not needed, since iteration index (run) and view will never be promises. Additionally add information about run in error messages about missing data (e.g. missing screenshot).

sitespeedio/sitespeed.io,sitespeedio/sitespeed.io,sitespeedio/sitespeed.io,beenanner/sitespeed.io,sitespeedio/sitespeed.io,beenanner/sitespeed.io,beenanner/sitespeed.io