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_test.cc b/motors/algorithms_test.cc
index bdf51d7..cf3ce3d 100644
--- a/motors/algorithms_test.cc
+++ b/motors/algorithms_test.cc
@@ -6,9 +6,7 @@
 
 #include "gtest/gtest.h"
 
-namespace frc971 {
-namespace motors {
-namespace testing {
+namespace frc971::motors::testing {
 
 class BalanceReadingsTest : public ::testing::Test {
  protected:
@@ -97,6 +95,4 @@
   CheckReadingsResult({{3424, 5013, 3424}, {2, 2, 2}});
 }
 
-}  // namespace testing
-}  // namespace motors
-}  // namespace frc971
+}  // namespace frc971::motors::testing