Windows compatability

[karanrampal]

cs230-code-examples/tensorflow/vision/build_dataset.py

Line 40 in 96ac6fd

image.save(os.path.join(output_dir, filename.split('/')[-1]))

I think we can maybe use os.path.basename(filename) instead of filename.split('/')[-1] as in windows os the paths to images get a \\ instead of /. Just with this change we can keep a consistent backslash system. Just a thought.