Add getters for x, y, theta in autonomous

Super handy for triggering behavior based on position.

Change-Id: I435617ffc786a48f51c7ed1c2cf75790300d2201
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/frc971/autonomous/base_autonomous_actor.h b/frc971/autonomous/base_autonomous_actor.h
index a70a440..5562dde 100644
--- a/frc971/autonomous/base_autonomous_actor.h
+++ b/frc971/autonomous/base_autonomous_actor.h
@@ -91,6 +91,11 @@
   // Returns true if the drive has finished.
   bool IsDriveDone();
 
+  // Returns the current x, y, theta of the robot on the field.
+  double X();
+  double Y();
+  double Theta();
+
   void LineFollowAtVelocity(
       double velocity,
       y2019::control_loops::drivetrain::SelectionHint hint =