PRUSA i3 MK3 Raspberry Pi 3 B+ Mount

THIS IS PART OF AN OVERALL Lack Enclosure design: https://www.thingiverse.com/thing:3129929

Remixed case with a tad more room for CPU heatsink.
Added cutout for camera cable and cut at the bottom for soldered/external power output.
Cutout added for pins required to connect to MK3 if desired.
Cooling ribs widened to promote better cooling when enclosed for ABS printing.