Run Testing on Multiple GPUs

[Raymondmax]

Is it possible to run the testing on multiple GPUs?
If yes, how to modify the configuration yml and code?

[Im34v]

I think the current version can't test on multiple GPUs. Because the dist_validation function in basicsr/models/sr_model directly uses nondist_validation function. So if we want to do that, we need to overwrite the dist_validation function in our models.