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/frc971/control_loops/control_loop_test.h b/frc971/control_loops/control_loop_test.h
index 00062b9..8b6ba09 100644
--- a/frc971/control_loops/control_loop_test.h
+++ b/frc971/control_loops/control_loop_test.h
@@ -16,8 +16,7 @@
 #include "frc971/input/joystick_state_generated.h"
 #include "frc971/input/robot_state_generated.h"
 
-namespace frc971 {
-namespace testing {
+namespace frc971::testing {
 
 // Handles setting up the environment that all control loops need to actually
 // run.
@@ -219,7 +218,6 @@
 constexpr ::std::chrono::milliseconds
     ControlLoopTestTemplated<TestBaseClass>::kDSPacketTime;
 
-}  // namespace testing
-}  // namespace frc971
+}  // namespace frc971::testing
 
 #endif  // AOS_CONTROLS_CONTROL_LOOP_TEST_H_