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/fixed_quadrature.h b/frc971/control_loops/fixed_quadrature.h
index 53bb0dc..88d52e8 100644
--- a/frc971/control_loops/fixed_quadrature.h
+++ b/frc971/control_loops/fixed_quadrature.h
@@ -5,8 +5,7 @@
 
 #include <Eigen/Dense>
 
-namespace frc971 {
-namespace control_loops {
+namespace frc971::control_loops {
 
 // Implements Gaussian Quadrature integration (5th order).  fn is the function
 // to integrate.  It must take 1 argument of type T.  The integration is between
@@ -57,7 +56,6 @@
   return answer;
 }
 
-}  // namespace control_loops
-}  // namespace frc971
+}  // namespace frc971::control_loops
 
 #endif  // FRC971_CONTROL_LOOPS_FIXED_QUADRATURE_H_