Diveboard v1

# Diveboard v1
## Summary
Derived from the Original OpenDive design, Diveboard v1 is my first attempt at unifying OpenDive and Google Cardboard.
## Specifics
This design is physically compatible with the original design and accessories, including the phone brackets, but includes several new features:
### The visor
* Rounded edges
* Rubber band anchors
* A top elastic tensioner
* An internal cutout for a 0.5" round magnet
* An external track for the Google Cardboard