Nest some more namespaces

Did someone previously suggest that all namespace had been
nested?  Silly.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I22278c1caaeba8b47dc46fb2ed3078c20a11e190
diff --git a/y2019/control_loops/superstructure/collision_avoidance.h b/y2019/control_loops/superstructure/collision_avoidance.h
index ac88cec..e872e8c 100644
--- a/y2019/control_loops/superstructure/collision_avoidance.h
+++ b/y2019/control_loops/superstructure/collision_avoidance.h
@@ -9,9 +9,7 @@
 #include "y2019/control_loops/superstructure/superstructure_goal_generated.h"
 #include "y2019/control_loops/superstructure/superstructure_status_generated.h"
 
-namespace y2019 {
-namespace control_loops {
-namespace superstructure {
+namespace y2019::control_loops::superstructure {
 
 // CollisionAvoidance computes the min and max allowable ranges for various
 // subsystems to avoid collisions.  It also shoves the elevator up to let the
@@ -108,8 +106,6 @@
   double max_intake_goal_;
 };
 
-}  // namespace superstructure
-}  // namespace control_loops
-}  // namespace y2019
+}  // namespace y2019::control_loops::superstructure
 
 #endif  // Y2019_CONTROL_LOOPS_SUPERSTRUCTURE_COLLISION_AVOIDANCE_H_