Initialize agitator-tracking branch

[psurge1]

Created agitator-tracking branch Added motor position and barrel sensor data inputs to the agitator subsystem

• Initialized left and right motor position controllers
• Called motor position and barrel sensor data inputs in Agitator Subsystem refresh function

[calebchalmers]

Alternating burst fire has been tested with Ash and seems to be working properly. Sadly, we can't test barrel heat properly without the server, so we'll assume it's good for now.

Sometimes too many balls are fired, which I believe is a combination of Ash's hardware and the way we're handling ball counting, which can be changed later if we need more accuracy.