integration tests for the fast training tutorials

[wyli]

Is your feature request related to a problem? Please describe.
would be great to set up integration tests so that the recommendations in the tutorials (https://github.com/Project-MONAI/tutorials/blob/master/acceleration/fast_model_training_guide.md) are up-to-date while the codebase evolves.

see also: #2676

[Nic-Ma]

Sure, let me try to make the integration test for fast training tutorial.

Thanks.