Chamfered Pi Camera mount

changed the mounting to use M3 bolts and T nuts and has a bottom to help guide the camera cable along the extrusion. ( I also used these clips to guide it the rest of the way https://www.thingiverse.com/thing:4867867)

The camera mount has chamfers added to remove the sharp corners, and M2 holes to allow for 6mm bolt to be added to lock the camera into position, with the original my cam would always sit slightly off angle to the printer frame.