Jupyter: straight-forward application of Truncated SVD on ResNet50

This is a simple application of Truncated SVD, just to get a feeling of
what happens to the accuracy if we use TruncatedSVD w/o fine-tuning.

We apply Truncated SVD on the linear layer found at the end of ResNet50,
and run a test over the validation dataset to measure the impact on the
classification accuracy.