Provide instructions for running benchmarks

[yaroslavvb]

It would be useful to have a readme to reproduce the benchmarks. For instance I found that for running cifar multi-gpu resnet on TF I needed to do pip install scikit-image

Also, it seems to look for CIFAR image data inside of /home/<username>/data/tensorflow/cifar10 for some reason, so I also had to do

cp -R <cifar datadir created when running official CIFAR example >/cifar-10-batches-bin /home/<username>/data/tensorflow/cifar10

[FreemanX]

We are working docs of this repo. As for the data, a symbolic link will work just fine if you want to save some space.