Fix simulation sent_time and add a test

It was hard-coded to the actual monotonic_clock::now() call, which
doesn't work well with actual simulation when you don't use fake time.
And we want to kill fake time.

Change-Id: If5785679d54100e5021bea86df763d98d44f7c3d
diff --git a/aos/events/simulated-event-loop_test.cc b/aos/events/simulated-event-loop_test.cc
index 7c11b4a..f652fd9 100644
--- a/aos/events/simulated-event-loop_test.cc
+++ b/aos/events/simulated-event-loop_test.cc
@@ -5,10 +5,12 @@
 namespace aos {
 namespace testing {
 
+namespace chrono = ::std::chrono;
+
 class SimulatedEventLoopTestFactory : public EventLoopTestFactory {
  public:
-  std::unique_ptr<EventLoop> Make() override {
-    return event_loop.CreateEventLoop();
+  ::std::unique_ptr<EventLoop> Make() override {
+    return event_loop.MakeEventLoop();
   }
  private:
    SimulatedEventLoopFactory event_loop;