Line 27, as of commit d16c532, cannot possibly throw a NullPointerException:
Code:
if((xAxis< deadBand) && (xAxis > -deadBand)){ xAxis=0;}
Are you sure the code on the robot is the same as the code on Github?
Edit: Ben's right. You declare the speed controllers in RobotMap, but never call init() so they're always going to be null.