IGUS RJ4JP-01-08 Holder

[EDIT: 3/Dec/17]
Made the bearing walls thicker and more structurally sound. Updated images and STL to account for this.

A remixed version of the bearing holder that [Phil_Maddox](https://www.thingiverse.com/thing:1404861) made, but I thought that the bevels on the edges were a little thin and left the bearing holder a little on the weak side (some of mine snapped with medium pressure) so I designed these through TinkerCAD for both a thicker cylindrical holder and also added support between