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/gaussian_noise.h b/frc971/control_loops/gaussian_noise.h
index dce60fb..a784df0 100644
--- a/frc971/control_loops/gaussian_noise.h
+++ b/frc971/control_loops/gaussian_noise.h
@@ -6,8 +6,7 @@
 #include <memory>
 #include <random>
 
-namespace frc971 {
-namespace control_loops {
+namespace frc971::control_loops {
 
 class GaussianNoise {
  public:
@@ -28,7 +27,6 @@
   std::normal_distribution<double> distribution_;
 };
 
-}  // namespace control_loops
-}  // namespace frc971
+}  // namespace frc971::control_loops
 
 #endif  // FRC971_CONTROL_LOOPS_GAUSSIAN_NOISE_H_