RaspberryPi3 Mk3 Case

I modified hackoholic version for adapt it to Original Prusa Mk3 and the Raspberry Pi 3 B.

Changes:
- When I printed other version I broke L2 regulator of a Raspberry Pi 3 B because the case pressed it so I reduced the surface that is in contact with the raspberry.

- Mk3 framework is narrower than the Mk2s so a couple of millimeter of case were inside printer area and could be touched bu extuder cables during the print. I modified to make this part fit with the framework.

- I added some holes in the "bottom" of the case in order to get a better heat dissipation.


I'm using it with Raspberry Pi 3 B+ and Prusa MK3.
It should be compatible with Raspberry Pi 2, Rapsberry Pi 3 B and also Prusa Mk2s.

The screws are from spare parts of Mk3 (4 x M3x18 and 2 x M3x10)