Problem: various tests fail in slow environments

Solution: add msleep (SETTLE_TIME) to test_immediate, test_spec_rep
and test_spec_router after the sockets are created and connected to
avoid failing when running in slower environment like through
Valgrind in underpowered VMs.

tests/test_spec_router.cpp

@@ -63,6 +63,8 @@ void test_fair_queue_in (void *ctx)
         assert (rc == 0);
     }
 
+    msleep (SETTLE_TIME);
+
     zmq_msg_t msg;
     rc = zmq_msg_init (&msg);
     assert (rc == 0);