Added logging configurations

Author: Yoichi Kawasaki

v2functions/host.json

@@ -1,3 +1,9 @@
 {
-    "version":  "2.0"
-}
+    "version":  "2.0",
+    "logger": {
+        "defaultLevel": "Trace",
+        "categoryLevels": {
+            "Worker": "Trace"
+        }
+    }
+}