add inference time to yolo plugin

plugins/yolo/shinobi-yolo.js

@@ -27,6 +27,7 @@ var yolo = require('node-yolo-shinobi');//this is @vapi/node-yolo@1.2.4 without
 // var yolo = require('@vapi/node-yolo');
 var detector = new yolo(__dirname + "/models", "cfg/coco.data", "cfg/yolov3.cfg", "yolov3.weights");
 s.detectObject=function(buffer,d,tx,frameLocation){
+    var timeStart = new Date()
     var detectStuff = function(frame,callback){
         detector.detect(frame)
              .then(detections => {
@@ -52,7 +53,8 @@ s.detectObject=function(buffer,d,tx,frameLocation){
                              reason:'object',
                              matrices:matrices,
                              imgHeight:parseFloat(d.mon.detector_scale_y),
-                             imgWidth:parseFloat(d.mon.detector_scale_x)
+                             imgWidth:parseFloat(d.mon.detector_scale_x),
+                             time: (new Date()) - timeStart
                          }
                      })
                  }