core+main: switch to std::thread and thread_local

Change-Id: I892eb7d87639c2b0d24a8ed457b9d32635269216
diff --git a/tests/rib-io-fixture.hpp b/tests/rib-io-fixture.hpp
index fa43af5..f2bb892 100644
--- a/tests/rib-io-fixture.hpp
+++ b/tests/rib-io-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) 2014-2019,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -27,9 +27,10 @@
 #define NFD_TESTS_RIB_IO_FIXTURE_HPP
 
 #include "tests/test-common.hpp"
-#include <boost/thread.hpp>
+
 #include <condition_variable>
 #include <mutex>
+#include <thread>
 
 namespace nfd {
 namespace tests {
@@ -66,7 +67,7 @@
 
   /** \brief global RIB thread
    */
-  boost::thread g_ribThread;
+  std::thread g_ribThread;
 
 private:
   bool m_shouldStopRibIo = false;