Assume angular uncertainty in auto is good

We align the robot really well in auto.  So we can assume that the
covariance of the heading is small.

Change-Id: Ifae45c36612476e21ce50987ccab8aa8846df86f
diff --git a/frc971/control_loops/drivetrain/localizer.q b/frc971/control_loops/drivetrain/localizer.q
index 1ae0adc..8fef686 100644
--- a/frc971/control_loops/drivetrain/localizer.q
+++ b/frc971/control_loops/drivetrain/localizer.q
@@ -6,6 +6,7 @@
   float x;      // X position, meters
   float y;      // Y position, meters
   float theta;  // heading, radians
+  double theta_uncertainty; // Uncertainty in theta.
 };
 
 queue LocalizerControl localizer_control;