Add localizer reset buttons to the drivetrain

This lets us recover without command line help.

Change-Id: Ia2ef1837a2ec1cf17ec1974832b1bd552e7c0e4a
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/frc971/input/drivetrain_input.h b/frc971/input/drivetrain_input.h
index 3419ea7..a33d449 100644
--- a/frc971/input/drivetrain_input.h
+++ b/frc971/input/drivetrain_input.h
@@ -94,6 +94,11 @@
   // Returns the current robot velocity in m/s.
   double robot_velocity() const { return robot_velocity_; }
 
+  // Returns the current drivetrain status.
+  const control_loops::drivetrain::Status *drivetrain_status() const {
+    return drivetrain_status_fetcher_.get();
+  }
+
   void set_vision_align_fn(
       ::std::function<bool(const ::frc971::input::driver_station::Data &data)>
           vision_align_fn) {