update app.py

app.py

@@ -4,15 +4,20 @@ import requests
 
 
 def test():
+    print('testing backend interface...')
     url = 'http://81.70.158.155:5005/predict'
     with open('./2680.jpg', 'rb') as f:
-        r = requests.post(url, files = {'image' : f})
-        ret = json.loads(r.text)
+	try:
+            r = requests.post(url, files = {'image' : f}, timeout=10)
+            ret = json.loads(r.text)
+        except Exception as e:
+            print('backend test failed')
+            return
 
     # image level cls score
     pred_cls_score = ret['cls_score']
     print('--------', pred_cls_score)
-
+    print('backend test success')
 
 def predict(img):
     url = 'http://81.70.158.155:5005/predict'