Wide-Bodied SCRU-FE

I needed a simple Arduino-based robot for working with schools, and I fell in love with the SCRU-FE design. It is easy to print, cheap to build, uses easily sourced parts, and with the ultrasonic sensor can introduce some programming to the students. Over the years I have probably built a couple of hundred or so with students, and during that time I've slowly evolved my own version to address some of the issues and challenges that came up.

The major changes are:

* Added ears. My wife complained that SCRU-FE looked ugly (I disagree) so I figured that if I added ears it would, by definition, become cute.
* Redesigned the ultrasonic mount to hold the sensor in place by pressure or screws without any additional components.
* Widened the body. I found that we would have trouble managing the wires and nuts inside the body due to the narrow space, so I widened the body to make things more accessible.
* Strengthened the sensor mount.
* Added holes for cable management.
* Added holes