Added superstructure test fixture.

This only tests the hood right now.  It needs to be split out into a
fixture and test cases file, and needs support for the other
subsystems.

Change-Id: I23bfbbc4c502939af6d388703771bcc340c4ffea
diff --git a/y2017/control_loops/superstructure/superstructure.h b/y2017/control_loops/superstructure/superstructure.h
index 036f0f8..c6a2742 100644
--- a/y2017/control_loops/superstructure/superstructure.h
+++ b/y2017/control_loops/superstructure/superstructure.h
@@ -35,9 +35,9 @@
     ESTOP = 4,
   };
 
-  bool IsRunning() const { return state_ == RUNNING; }
+  const hood::Hood &hood() const { return hood_; }
 
-  State state() const { return state_; }
+  bool IsRunning() const { return state_ == RUNNING; }
 
   // Returns the value to move the joint to such that it will stay below
   // reference_angle starting at current_angle, but move at least move_distance