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/y2021_bot3/joystick_reader.cc b/y2021_bot3/joystick_reader.cc
index 0e5076a..dc60c6e 100644
--- a/y2021_bot3/joystick_reader.cc
+++ b/y2021_bot3/joystick_reader.cc
@@ -23,9 +23,7 @@
 using frc971::input::driver_station::JoystickAxis;
 using frc971::input::driver_station::POVLocation;
 
-namespace y2021_bot3 {
-namespace input {
-namespace joysticks {
+namespace y2021_bot3::input::joysticks {
 
 namespace superstructure = y2021_bot3::control_loops::superstructure;
 
@@ -59,9 +57,7 @@
   ::aos::Fetcher<superstructure::Status> superstructure_status_fetcher_;
 };
 
-}  // namespace joysticks
-}  // namespace input
-}  // namespace y2021_bot3
+}  // namespace y2021_bot3::input::joysticks
 
 int main(int argc, char **argv) {
   ::aos::InitGoogle(&argc, &argv);