measurement script - provide inputs via env file

[KrzysztofHajdamowicz]

Hey,

Currently, measurement script asks various questions before it start taking measurements.
My idea is to extend the script by allowing to pre-populate those inputs via .env file, thus it's easier to make docker self-restart when issue happens and script fails.

[jacobdonenfeld]

I like this idea

[bramstroker]

Good news guys. This is implemented with #713. Will be in next release.