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/motors/algorithms.cc b/motors/algorithms.cc
index 6edb532..c429a84 100644
--- a/motors/algorithms.cc
+++ b/motors/algorithms.cc
@@ -1,7 +1,6 @@
 #include "motors/algorithms.h"
 
-namespace frc971 {
-namespace motors {
+namespace frc971::motors {
 
 BalancedReadings BalanceReadings(const ReadingsToBalance to_balance) {
   // TODO(Brian): Get rid of the floating point divides.
@@ -46,5 +45,4 @@
   return result;
 }
 
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors