tests: respect naming conventions and improve nesting of some test suites

Change-Id: I65af858bc6d10197c6ee11111fa9f7c1faa617ef
Refs: #2497
diff --git a/tests/daemon/mgmt/face-manager-command-fixture.hpp b/tests/daemon/mgmt/face-manager-command-fixture.hpp
index fcb89a4..8d66309 100644
--- a/tests/daemon/mgmt/face-manager-command-fixture.hpp
+++ b/tests/daemon/mgmt/face-manager-command-fixture.hpp
@@ -29,18 +29,17 @@
 #include "mgmt/face-manager.hpp"
 #include "fw/face-table.hpp"
 
+#include "tests/identity-management-fixture.hpp"
+
 #include <ndn-cxx/mgmt/dispatcher.hpp>
 #include <ndn-cxx/util/dummy-client-face.hpp>
 
-#include "tests/identity-management-fixture.hpp"
-
 namespace nfd {
 namespace tests {
 
 class FaceManagerCommandNode
 {
 public:
-  explicit
   FaceManagerCommandNode(ndn::KeyChain& keyChain, uint16_t port);
 
   ~FaceManagerCommandNode();