External bearing bottom bracket tool

Modified [FatGeekyMan](https://www.thingiverse.com/FatGeekyMan)'s [tool](https://www.thingiverse.com/thing:773975) a bit to have more round corners. Also added a modifier part to add stiffness to teeth and handle while using a low density infill to reduce overall filament usage.

External bearing bottom bracket wrench compatible with:
- Shimano Hollowtech II
- Campagnolo Ulta-Torque and Power Torque
- Race Face
- FSA
- SRAM
- Truvativ

Slicing using Slic3r's modifier part feature: https://youtu.be/kdgvXvhe9ms