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/dashboard/dashboard.cc b/y2016/dashboard/dashboard.cc
index 0b12b14..319eaa5 100644
--- a/y2016/dashboard/dashboard.cc
+++ b/y2016/dashboard/dashboard.cc
@@ -25,8 +25,7 @@
 
 namespace chrono = ::std::chrono;
 
-namespace y2016 {
-namespace dashboard {
+namespace y2016::dashboard {
 namespace big_indicator {
 constexpr int kBlack = 0;
 constexpr int kBallIntaked = 1;
@@ -275,8 +274,7 @@
   data_collector_thread_.join();
 }
 
-}  // namespace dashboard
-}  // namespace y2016
+}  // namespace y2016::dashboard
 
 int main(int argc, char **argv) {
   // Make sure to reference this to force the linker to include it.