Add Climber class and tests

For now, it is a simple pass through.

Change-Id: I5274b03f6ade23fbc98713cf8ed849866a85b429
diff --git a/y2020/control_loops/superstructure/superstructure.h b/y2020/control_loops/superstructure/superstructure.h
index 8fae9c5..2bc0cda 100644
--- a/y2020/control_loops/superstructure/superstructure.h
+++ b/y2020/control_loops/superstructure/superstructure.h
@@ -8,6 +8,7 @@
 #include "y2020/control_loops/superstructure/superstructure_output_generated.h"
 #include "y2020/control_loops/superstructure/superstructure_position_generated.h"
 #include "y2020/control_loops/superstructure/superstructure_status_generated.h"
+#include "y2020/control_loops/superstructure/climber.h"
 
 namespace y2020 {
 namespace control_loops {
@@ -42,6 +43,7 @@
   AbsoluteEncoderSubsystem intake_joint_;
   PotAndAbsoluteEncoderSubsystem turret_;
 
+  Climber climber_;
   DISALLOW_COPY_AND_ASSIGN(Superstructure);
 };