tests: sync common testing infrastructure with ndn-cxx

Change-Id: I6feab5247231abc35b8daa96bca21ad17c9cc4b3
diff --git a/tests/tools/mock-nfd-mgmt-fixture.hpp b/tests/tools/mock-nfd-mgmt-fixture.hpp
index 40dc3ba..7c02720 100644
--- a/tests/tools/mock-nfd-mgmt-fixture.hpp
+++ b/tests/tools/mock-nfd-mgmt-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2020,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -26,7 +26,7 @@
 #ifndef NFD_TESTS_TOOLS_MOCK_NFD_MGMT_FIXTURE_HPP
 #define NFD_TESTS_TOOLS_MOCK_NFD_MGMT_FIXTURE_HPP
 
-#include "tests/clock-fixture.hpp"
+#include "tests/io-fixture.hpp"
 #include "tests/key-chain-fixture.hpp"
 #include "tests/test-common.hpp"
 
@@ -45,12 +45,11 @@
 
 /** \brief Fixture to emulate NFD management.
  */
-class MockNfdMgmtFixture : public ClockFixture, public KeyChainFixture
+class MockNfdMgmtFixture : public IoFixture, public KeyChainFixture
 {
 protected:
   MockNfdMgmtFixture()
-    : ClockFixture(m_io)
-    , face(m_io, m_keyChain,
+    : face(m_io, m_keyChain,
            {true, false, bind(&MockNfdMgmtFixture::processEventsOverride, this, _1)})
   {
     face.onSendInterest.connect([this] (const Interest& interest) {
@@ -206,9 +205,6 @@
     signData(data);
   }
 
-private:
-  boost::asio::io_service m_io;
-
 protected:
   ndn::util::DummyClientFace face;
   std::function<void(const Interest&)> processInterest;