Made the roller command uninterruptible in the hope that this would keep the roller motor going as we open and close the pickup arm.
I have no explanation for why this might help, but it seemed worth a shot since there is no other command that uses the RollerSubsys.
I also create a static GYRO_START_ANGLE which is set in autonomousInit before starting the autonomousCommand. This static is used in the autonomousCommand to adjust the turn angle passed in to turn90 to account for any drift of the robot while driving or stopping during the autonomousDrive.