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/frc971/shooter_interpolation/interpolation_test.cc b/frc971/shooter_interpolation/interpolation_test.cc
index 92a2b76..3409282 100644
--- a/frc971/shooter_interpolation/interpolation_test.cc
+++ b/frc971/shooter_interpolation/interpolation_test.cc
@@ -8,8 +8,7 @@
 
 #include "gtest/gtest.h"
 
-namespace frc971 {
-namespace shooter_interpolation {
+namespace frc971::shooter_interpolation {
 
 struct TestShotParams {
   double angle;
@@ -72,5 +71,4 @@
   ASSERT_EQ(TestShotParams({10, 567.323}), interpolation.Get(5));
 }
 
-}  // namespace shooter_interpolation
-}  // namespace frc971
+}  // namespace frc971::shooter_interpolation