Spool Mount for 2020 Extrusion

I loved dintid's great filament spool holder (http://www.thingiverse.com/thing:1000323). I just wanted to change the mount for it to use 5mm screw for the v-slot - move them in from the edge to give it a bit more strength.

Also, I added some slope to the pieces so they can be printed on end without any support.

There are 3 different mounts (matching what dintid had):
1 - Mount with guides on the side and for the v-slot
2 - Mount with just v-slot guide
3 - Mount with no guides