Problem: no unit tests

Solution: set up initial unit tests

unittests/unittest_poller.cpp

@@ -0,0 +1,47 @@
+/*
+Copyright (c) 2018 Contributors as noted in the AUTHORS file
+
+This file is part of 0MQ.
+
+0MQ is free software; you can redistribute it and/or modify it under
+the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 3 of the License, or
+(at your option) any later version.
+
+0MQ is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "../tests/testutil.hpp"
+
+#include <poller.hpp>
+
+#include <unity.h>
+
+void setUp ()
+{
+}
+void tearDown ()
+{
+}
+
+void test_create ()
+{
+    zmq::thread_ctx_t thread_ctx;
+    zmq::poller_t poller (thread_ctx);
+}
+
+int main (void)
+{
+    setup_test_environment ();
+
+    UNITY_BEGIN ();
+    RUN_TEST (test_create);
+
+    return UNITY_END ();
+}