sysd_monitor: Initial application framework

This sets the base for a sequence of commits which will enable the
functionality defined within this design document:
https://github.com/openbmc/docs/blob/master/designs/target-fail-monitoring.md

All TODO comments will be complete by the end of this patch set
sequence.

Change-Id: Ifb263ad5e4db6f07fe0b1a4638fb052e5d8beaa5
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/systemd_target_monitor.cpp b/systemd_target_monitor.cpp
new file mode 100644
index 0000000..b9af29f
--- /dev/null
+++ b/systemd_target_monitor.cpp
@@ -0,0 +1,18 @@
+#include <sdbusplus/bus.hpp>
+#include <sdeventplus/event.hpp>
+
+int main(int argc, char* argv[])
+{
+    auto bus = sdbusplus::bus::new_default();
+    auto event = sdeventplus::Event::get_default();
+    bus.attach_event(event.get(), SD_EVENT_PRIORITY_NORMAL);
+
+    // TODO - Process input parameters
+
+    // TODO - Load in json config file(s)
+
+    // TODO - Begin monitoring for systemd unit changes and logging appropriate
+    //        errors
+
+    return event.loop();
+}