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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/y2018/control_loops/superstructure/debouncer.cc b/y2018/control_loops/superstructure/debouncer.cc
index 40b730d..98e80f3 100644
--- a/y2018/control_loops/superstructure/debouncer.cc
+++ b/y2018/control_loops/superstructure/debouncer.cc
@@ -1,8 +1,6 @@
 #include "y2018/control_loops/superstructure/debouncer.h"
 
-namespace y2018 {
-namespace control_loops {
-namespace superstructure {
+namespace y2018::control_loops::superstructure {
 
 void Debouncer::Update(bool new_state) {
   // If the incoming state is different from the one we have stored, increment
@@ -20,6 +18,4 @@
   }
 }
 
-}  // namespace superstructure
-}  // namespace control_loops
-}  // namespace y2018
+}  // namespace y2018::control_loops::superstructure