face: replace EventEmitter usage with Signal

refs #2300

Change-Id: I17d0d65d2c474b17dd9f23f271a6144b0b4fbc07
diff --git a/tests/daemon/face/face.cpp b/tests/daemon/face/face.cpp
index 143dfe6..a8f397a 100644
--- a/tests/daemon/face/face.cpp
+++ b/tests/daemon/face/face.cpp
@@ -65,7 +65,7 @@
   FaceFailTestFace()
     : failCount(0)
   {
-    this->onFail += bind(&FaceFailTestFace::failHandler, this, _1);
+    this->onFail.connect(bind(&FaceFailTestFace::failHandler, this, _1));
   }
 
   void