[ONNX] Use ONNX_TF and nGraph_ONNX to do inference/prediction with ONNX model

Here I try to use the pre-trained model from ONNX model zoo, which the models are already converted from some deep learning framework. So I download the Resnet50 model from the following URL and untar it:

wget https://s3.amazonaws.com/download.onnx/models/opset_8/resnet50.tar.gz
tar -xzvf resnet50.tar.gz 

P.S: pre-trained ONNX models: https://github.com/onnx/models

Then, I can do the inference/prediction using this ONNX model in two ways: