change download link to Baidu bos (#40)

server/visualdl/mock/download_mock_models.sh

 
 # Download inception_v1 model
-curl -LOk https://s3.amazonaws.com/download.onnx/models/inception_v1.tar.gz
+curl -LOk http://visualdl.bj.bcebos.com/inception_v1.tar.gz
 
 tar -xvzf inception_v1.tar.gz
 cp inception_v1/model.pb inception_v1_model.pb
@@ -10,7 +10,7 @@ rm inception_v1.tar.gz
 
 
 # Download squeezenet model
-curl -LOk https://s3.amazonaws.com/download.onnx/models/squeezenet.tar.gz
+curl -LOk http://visualdl.bj.bcebos.com/squeezenet.tar.gz
 
 tar -xvzf squeezenet.tar.gz
 cp squeezenet/model.pb squeezenet_model.pb