onnx should be 1.6.0

for smoothly export model to onnx, onnx should be 1.6.0

requirements.txt

@@ -21,4 +21,4 @@ git+https://github.com/cocodataset/cocoapi.git#subdirectory=PythonAPI
 # conda install -yc conda-forge scikit-image pycocotools tensorboard
 # conda install -yc spyder-ide spyder-line-profiler
 # conda install -yc pytorch pytorch torchvision
-# conda install -yc conda-forge protobuf numpy && pip install onnx  # https://github.com/onnx/onnx#linux-and-macos
+# conda install -yc conda-forge protobuf numpy && pip install onnx==1.6.0  # https://github.com/onnx/onnx#linux-and-macos