CNC'd Shipping Container Box

This is a simplified, derived version of Iron Mammoth's [Laser Cut Shipping Container Box](http://ironmammoth.blogspot.com/2015/06/laser-cut-shipping-container-build.html), and is shared here with his permission. I modified it for cutting on a CNC router, and built 24 of them on my Inventables X-Carve for the [O'Reilly IoT Learning Lab at LiveWorx 2016 sponsored by PTC](http://www.liveworx.com/Developers#show_or). During the Lab, we filled the box with a Raspberry Pi and some sensors, and connec