Nest some more namespaces

Did someone previously suggest that all namespace had been
nested?  Silly.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I22278c1caaeba8b47dc46fb2ed3078c20a11e190
diff --git a/y2020/actors/auto_splines.h b/y2020/actors/auto_splines.h
index e7bef0a..396fe4b 100644
--- a/y2020/actors/auto_splines.h
+++ b/y2020/actors/auto_splines.h
@@ -13,8 +13,7 @@
 
 */
 
-namespace y2020 {
-namespace actors {
+namespace y2020::actors {
 
 class AutonomousSplines {
  public:
@@ -89,7 +88,6 @@
   aos::FlatbufferDetachedBuffer<frc971::MultiSpline> far_side_fender_;
 };
 
-}  // namespace actors
-}  // namespace y2020
+}  // namespace y2020::actors
 
 #endif  // y2020_ACTORS_AUTO_SPLINES_H_