Simplify configuration of newly flashed Raspberry Pis

[mbfm]

Users should be able to easily flash a Raspberry Pi, so that they can then run additional configuration scripts and roll out EDGAR.

For this, we want to provide a flashing script which provisions an SD card, which when booted in a Raspberry Pi spans a WiFi hotspot, to which you can connect and then SSH into the Raspberry Pi in a deterministic manner.