Support ONNX?

Hi there,

Great job, and I'm looking forward to use it and compare with other frameworks like E2FGVI.

Just wondering do you plan to convert the model to Onnx format? I think that would be a great advantages if the model would evaluate on multiple devices. I've tried converting model of E2FGVI to ONNX, but failed(Since it has mmcv customer modules which is hard to convert).

Thanks.