Case for ESP12F_RELAY_X8 board

I resized and adjusted the great model from @dewgenenny.

It fits the 8x Relay board now, what I changed apart from the size was:

• replaced the guides to fit M3 screws and nuts (the nuts I fixed with superglue in place)
• Changed the holes to screw/unscrew the sockets
• Made cutouts for the array in the spacers
• TODO: Add a hole to give access to the reset button (on mine I drilled a hole)

The nut holder parts print quite bad but are more than strong enough anyway.

I printed it in ABS and PLA.