Unofficial pytorch 0.4 support

Hi

I had some issues running the test set for fastai http://forums.fast.ai/t/error-running-pytest/21476 I managed to get the test set to run but my methods are perhaps not what is wanted. Using PYTHONPATH environment variable would have issues with maintaining a consistent view with the source activate environment. I took my paths from a python session after importing sys and printing the sys.path to output. Then quit python session. This gave me the main anaconda environment paths not the source activated ones. I just edited it by adding envs/fastai-cpu in the right places. There are probably more paths in that group than are required. Do you have any suggestions of how to get the right paths automatically . Thanks