Add download tests for remaining datasets (#3338)
Add download tests for remaining datasets (#3338)

* kmnist

* emnist

* qmnist

* omniglot

* phototour

* sbdataset

* sbu

* semeion

* stl10

* svhn

* usps

* cifar100

* enable download logging for google drive

* celeba

* widerface

* lint

* add timeout logic

* lint

* debug CI connection to problematic server

* set timeout for ping

* [ci skip] remove ping

* revert debugging

* disable requests to problematic server

* re-enable all other tests

Co-authored-by: Vasilis Vryniotis <d748cd3f763058dcf20e5489b9bc2373b78db68c@users.noreply.github.com>
pytorch/vision,pytorch/vision,pytorch/vision,pytorch/vision,pytorch/vision,pytorch/vision