tests: resetGlobalIoService for every test

All tests must use BaseFixture or a fixture derived from it to get this feature.

This commit also fixes a few warnings in tests/mgmt, and moves test cases into nfd::tests namespace.

refs #1290

Change-Id: I891441a5abce170e35648d463f7157b18429f79f
diff --git a/tests/face/ethernet.cpp b/tests/face/ethernet.cpp
index 6803a1a..cd84008 100644
--- a/tests/face/ethernet.cpp
+++ b/tests/face/ethernet.cpp
@@ -5,14 +5,14 @@
  */
 
 #include "face/ethernet-channel-factory.hpp"
-
 #include <ndn-cpp-dev/security/key-chain.hpp>
 
-#include <boost/test/unit_test.hpp>
+#include "tests/test-common.hpp"
 
 namespace nfd {
+namespace tests {
 
-BOOST_AUTO_TEST_SUITE(FaceEthernet)
+BOOST_FIXTURE_TEST_SUITE(FaceEthernet, BaseFixture)
 
 BOOST_AUTO_TEST_CASE(MulticastFacesMap)
 {
@@ -104,4 +104,5 @@
 
 BOOST_AUTO_TEST_SUITE_END()
 
+} // namespace tests
 } // namespace nfd