tests: unit-tests-{core,tools} no longer require a global io_service

BaseFixture is moved to tests/daemon and renamed to GlobalIoFixture

Refs: #4528
Change-Id: If9184e9f7f1d6072b0103d3ea3ca6c31a9e505c8
diff --git a/tests/test-common.hpp b/tests/test-common.hpp
index 775c032..63b1a99 100644
--- a/tests/test-common.hpp
+++ b/tests/test-common.hpp
@@ -26,9 +26,8 @@
 #ifndef NFD_TESTS_TEST_COMMON_HPP
 #define NFD_TESTS_TEST_COMMON_HPP
 
-#include "boost-test.hpp"
-
-#include "tests/clock-fixture.hpp"
+#include "core/common.hpp"
+#include "tests/boost-test.hpp"
 
 #include <ndn-cxx/prefix-announcement.hpp>
 
@@ -48,36 +47,6 @@
 namespace nfd {
 namespace tests {
 
-/** \brief base test fixture
- *
- *  Every test case should be based on this fixture,
- *  to have per test case io_service initialization.
- */
-class BaseFixture
-{
-protected:
-  BaseFixture();
-
-  virtual
-  ~BaseFixture();
-
-protected:
-  /** \brief reference to global io_service
-   */
-  boost::asio::io_service& g_io;
-};
-
-/** \brief a base test fixture that overrides steady clock and system clock
- */
-class UnitTestTimeFixture : public virtual BaseFixture, public ClockFixture
-{
-protected:
-  UnitTestTimeFixture()
-    : ClockFixture(g_io)
-  {
-  }
-};
-
 /** \brief create an Interest
  *  \param name Interest name
  *  \param nonce if non-zero, set Nonce to this value