Restructure the code so that it is unit testable

Change-Id: I2af7a26d054522beae82f58769f8c2420a22eca2
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/network_manager_main.cpp b/network_manager_main.cpp
index 5e79566..a53d32c 100644
--- a/network_manager_main.cpp
+++ b/network_manager_main.cpp
@@ -12,6 +12,8 @@
 
     phosphor::network::Manager manager(bus, OBJ_NETWORK);
 
+    manager.createInterfaces();
+
     bus.request_name(BUSNAME_NETWORK);
 
     while(true)