Customizable Spool Holder Axis

### Update Description V2: 2019/08/14
Thanks to [@emaayan](https://www.thingiverse.com/emaayan)'s [cool suggestion](https://www.thingiverse.com/thing:2846481/comments/#comment-2640132), I made a V2. There are now two more options:
* **Two part cylinders for left/right plugging:** you match the diameter of the spool exactly and have two parts that you plug in from both sites of the spool.
* **Above thing, but gluable:** makes for better rigidity at the bearing axis, as the printing orientation