Merge branch 'add_seeinthedark_module' of...

Merge branch 'add_seeinthedark_module' of https://github.com/rainyfly/PaddleHub into add_seeinthedark_module

modules/video/multiple_object_tracking/fairmot_dla34/README.md

@@ -53,7 +53,7 @@
     ```
   - 通过命令行方式实现多目标追踪模型的调用，更多请见 [PaddleHub命令行指令](../../../../docs/docs_ch/tutorial/cmd_usage.rst)
 
-- ### 2、代码示例
+- ### 2、预测代码示例
 
   - ```python
     import paddlehub as hub

modules/video/multiple_object_tracking/fairmot_dla34/tracker.py

@@ -41,6 +41,7 @@ class StreamTracker(object):
         self.optimizer = None
 
         # build model
+        with paddle.no_grad():
             self.model = create(cfg.architecture)
 
         self.status = {}

modules/video/multiple_object_tracking/jde_darknet53/README.md

@@ -55,7 +55,7 @@
     ```
   - 通过命令行方式实现多目标追踪模型的调用，更多请见 [PaddleHub命令行指令](../../../../docs/docs_ch/tutorial/cmd_usage.rst)
 
-- ### 2、代码示例
+- ### 2、预测代码示例
 
   - ```python
     import paddlehub as hub