DOLPi Camera Chassis

This is a simple chassis for the [DOLPi-Mech polarization imager developed by David Prutchi](http://www.diyphysics.com/2015/08/24/dolpi_mech-a-slower-but-accurate-imaging-polarimeter/). The imager consists of a Raspberry Pi and Pi Camera to collect images, a printed filter wheel to hold the polarizing films, a servo and Adafruit ServoHat to rotate the filter wheel, and a mounting plate to hold it all together.

I won't document the usage for the camera itself. David Prutchi has done an amazing job of that in [the lengthy write up provided on his blog](http://www.diyphysics.com/2015/10/26/dolpi-final-version-of-whitepaper-and-video/). One thing I will mention, though, is that the software in David's white paper won't work without a bit of tinkering. In particular, the Adafruit ServoHat now uses libraries called ServoKit, so you'll need to adapt the software to use ServoKit. ServoKit requires Python 3, and the imager software also requires the use of OpenCV, which takes a little bit of