Making a submission with a macOSx?

#1

Participants should be able to make a valid submission with macOS (in fact simply from their browser, if they fork the repository, change the code using the web IDE and release a tag). For evaluating an already trained model, we use disentanglement_lib which depends on tensorflow. Thus to evaluate the submissions locally on macOS using local_evaluation.py, one needs to install the CPU version of tensorflow as tensorflow doesn’t provide GPU support for macOS. To do this, simply replace tensorflow-gpu with tensorflow in the requirements.txt.