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/wpilib_interface.cc b/y2021_bot3/wpilib_interface.cc
index 6f5908c..4006736 100644
--- a/y2021_bot3/wpilib_interface.cc
+++ b/y2021_bot3/wpilib_interface.cc
@@ -59,8 +59,7 @@
 namespace chrono = ::std::chrono;
 using std::make_unique;
 
-namespace y2021_bot3 {
-namespace wpilib {
+namespace y2021_bot3::wpilib {
 namespace {
 
 constexpr double kMaxBringupPower = 12.0;
@@ -354,7 +353,6 @@
   }
 };
 
-}  // namespace wpilib
-}  // namespace y2021_bot3
+}  // namespace y2021_bot3::wpilib
 
 AOS_ROBOT_CLASS(::y2021_bot3::wpilib::WPILibRobot);