Show progress during `check-setup`

[corneliusroemer]

nextstrain check-setup takes almost a minute despite having a fast M1 Pro. There's no progress indicator which might be confusing to users who are running it for the first time.

It might be good to give an indication how long this check takes. E.g. "Testing your setup... (this takes about a minute)"

Even better would be some sort of progress indication after each runtime is checked, maybe outputting it or indicating that it has been checked successfully.

[tsibley]

Yeah, check-setup hasn't gotten a lot of attention. It could use some!