Nest all namespaces

The compiler supports this now.  We can type less going forward.
No functional changes.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I29d6fa4f9aacc0e381f1a7637294db0392466995
diff --git a/y2016/control_loops/superstructure/superstructure.cc b/y2016/control_loops/superstructure/superstructure.cc
index 88dfd93..7b69534 100644
--- a/y2016/control_loops/superstructure/superstructure.cc
+++ b/y2016/control_loops/superstructure/superstructure.cc
@@ -8,9 +8,7 @@
 #include "y2016/control_loops/superstructure/superstructure_controls.h"
 #include "y2016/queues/ball_detector_generated.h"
 
-namespace y2016 {
-namespace control_loops {
-namespace superstructure {
+namespace y2016::control_loops::superstructure {
 
 namespace {
 // The maximum voltage the intake roller will be allowed to use.
@@ -846,6 +844,4 @@
 constexpr double Superstructure::kShoulderWristClearAngle;
 constexpr double Superstructure::kShoulderTransitionToLanded;
 
-}  // namespace superstructure
-}  // namespace control_loops
-}  // namespace y2016
+}  // namespace y2016::control_loops::superstructure