Intialize new phosphor-time-manager

phosphor-time-manager will be refactored to use sdbusplus interfaces.
This is a initial commit that EpochBase is implemented based on dbus
interface xyz/openbmc_project/Time/EpochTime.interface.yaml.

EpochBase is the base class that wraps EpochTime interface, and is
initialized with time mode and owner from settingsd.

An initial unit test case is added.

Change-Id: Ic944b70f63ec3c0329762cc8874f0f57b09ddce3
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..0cf2807
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,17 @@
+#include <sdbusplus/bus.hpp>
+
+#include "config.h"
+
+int main()
+{
+    auto bus = sdbusplus::bus::new_default();
+
+    bus.request_name(BUSNAME);
+
+    while (true)
+    {
+        bus.process_discard();
+        bus.wait();
+    }
+    return 0;
+}