Emit an interfaces added signal

Resolves openbmc/openbmc#1710

Change-Id: Ibbda0fa52de6a569418db939f6527ff985e869e9
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/manager.cpp b/manager.cpp
index ffde98e..97d629b 100644
--- a/manager.cpp
+++ b/manager.cpp
@@ -218,7 +218,7 @@
     }
     else if (!signals.empty())
     {
-        // TODO: emit an interfaces added signal
+        _bus.emit_interfaces_added(path.str.c_str(), signals);
     }
 }