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/y2014/joystick_reader.cc b/y2014/joystick_reader.cc
index 5349334..232a0ce 100644
--- a/y2014/joystick_reader.cc
+++ b/y2014/joystick_reader.cc
@@ -25,9 +25,7 @@
 
 #define OLD_DS 0
 
-namespace y2014 {
-namespace input {
-namespace joysticks {
+namespace y2014::input::joysticks {
 
 const ButtonLocation kDriveControlLoopEnable1(1, 7),
     kDriveControlLoopEnable2(1, 11);
@@ -441,9 +439,7 @@
                                      "no drivetrain status");
 };
 
-}  // namespace joysticks
-}  // namespace input
-}  // namespace y2014
+}  // namespace y2014::input::joysticks
 
 int main(int argc, char **argv) {
   ::aos::InitGoogle(&argc, &argv);