Build firmwares, possibly using https://nerves-project.org/

[marcoherbst]

TBH I am not entirely sure of the benefit of this over Etcher but I would be curious to see it in action.

Possibly relevant:
Ability to get the serial number of the board https://github.com/nerves-project/boardid which might help in #155 allowing the device, on first boot, to identify itself to Evercam Deployment Server.

[marcoherbst]

I think this issue can be closed as it's contained in #155