Add `list_benchmarks` to compare models easily

[MohamedAliRashad]

This is a simple function for listing ImageNet benchmarks found here for users to see

[kaczmarj]

adding pandas as a requirement might not be great, and the function is simple enough to be done without pandas. could you rework this to use the standard library? urllib to download the file, and then the csv module to load the data, for example.

[MohamedAliRashad]

@kaczmarj Adding pandas to the list of dependinces will provide room in the future for more features to be added. I can do what you want if this what you think is best for the project.