Add distance remaining to trajectory status

Change-Id: I76b08464483f141aadae88ed53ca5814e1f75081
diff --git a/frc971/control_loops/drivetrain/drivetrain.q b/frc971/control_loops/drivetrain/drivetrain.q
index 939ad75..c6af732 100644
--- a/frc971/control_loops/drivetrain/drivetrain.q
+++ b/frc971/control_loops/drivetrain/drivetrain.q
@@ -63,6 +63,7 @@
   float theta;
   float left_velocity;
   float right_velocity;
+  float distance_remaining;
 };
 
 // For logging state of the line follower.