Migrate to C++17 and misc code cleanups

Change-Id: I6b63385c92361a7ef5803d2bfd00f39c77e88d34
diff --git a/tests/integrated/command-fixture.cpp b/tests/integrated/command-fixture.cpp
index ad7955a..28990e3 100644
--- a/tests/integrated/command-fixture.cpp
+++ b/tests/integrated/command-fixture.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2018, Regents of the University of California.
+ * Copyright (c) 2014-2022, Regents of the University of California.
  *
  * This file is part of NDN repo-ng (Next generation of NDN repository).
  * See AUTHORS.md for complete list of repo-ng authors and contributors.
@@ -19,8 +19,7 @@
 
 #include "command-fixture.hpp"
 
-namespace repo {
-namespace tests {
+namespace repo::tests {
 
 CommandFixture::CommandFixture()
   : scheduler(repoFace.getIoService())
@@ -33,5 +32,4 @@
   validator.load("tests/integrated/insert-delete-validator-config.conf");
 }
 
-} // namespace tests
-} // namespace repo
+} // namespace repo::tests
diff --git a/tests/integrated/command-fixture.hpp b/tests/integrated/command-fixture.hpp
index 601f0b9..6d4aa44 100644
--- a/tests/integrated/command-fixture.hpp
+++ b/tests/integrated/command-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2018, Regents of the University of California.
+ * Copyright (c) 2014-2022, Regents of the University of California.
  *
  * This file is part of NDN repo-ng (Next generation of NDN repository).
  * See AUTHORS.md for complete list of repo-ng authors and contributors.
@@ -21,11 +21,11 @@
 #define REPO_TESTS_INTEGRATED_COMMAND_FIXTURE_HPP
 
 #include "../identity-management-fixture.hpp"
-#include <ndn-cxx/security/validator-null.hpp>
-#include <ndn-cxx/mgmt/dispatcher.hpp>
 
-namespace repo {
-namespace tests {
+#include <ndn-cxx/mgmt/dispatcher.hpp>
+#include <ndn-cxx/security/validator-config.hpp>
+
+namespace repo::tests {
 
 class CommandFixture : public virtual IdentityManagementFixture
 {
@@ -35,13 +35,12 @@
 protected:
   Face repoFace;
   Scheduler scheduler;
-  KeyChain& keyChain;
+  ndn::KeyChain& keyChain;
   ndn::mgmt::Dispatcher dispatcher;
   /// \todo #4091 switch to ValidatorPolicyConf and load insert-delete-validator-config.conf
-  ValidatorConfig validator;
+  ndn::security::ValidatorConfig validator;
 };
 
-} // namespace tests
-} // namespace repo
+} // namespace repo::tests
 
 #endif // REPO_TESTS_INTEGRATED_COMMAND_FIXTURE_HPP
diff --git a/tests/integrated/test-basic-command-insert-delete.cpp b/tests/integrated/test-basic-command-insert-delete.cpp
index 5ed5b9b..55d6e65 100644
--- a/tests/integrated/test-basic-command-insert-delete.cpp
+++ b/tests/integrated/test-basic-command-insert-delete.cpp
@@ -35,8 +35,7 @@
 #include <boost/mpl/vector.hpp>
 #include <boost/test/unit_test.hpp>
 
-namespace repo {
-namespace tests {
+namespace repo::tests {
 
 using ndn::time::milliseconds;
 
@@ -288,5 +287,4 @@
 
 BOOST_AUTO_TEST_SUITE_END()
 
-} // namespace tests
-} // namespace repo
+} // namespace repo::tests
diff --git a/tests/integrated/test-basic-interest-read.cpp b/tests/integrated/test-basic-interest-read.cpp
index ab3da01..ed62466 100644
--- a/tests/integrated/test-basic-interest-read.cpp
+++ b/tests/integrated/test-basic-interest-read.cpp
@@ -27,10 +27,7 @@
 #include <boost/asio/io_service.hpp>
 #include <boost/test/unit_test.hpp>
 
-#include <ndn-cxx/util/time.hpp>
-
-namespace repo {
-namespace tests {
+namespace repo::tests {
 
 BOOST_AUTO_TEST_SUITE(TestBasicInterestRead)
 
@@ -127,5 +124,4 @@
 
 BOOST_AUTO_TEST_SUITE_END()
 
-} // namespace tests
-} // namespace repo
+} // namespace repo::tests