For anyone using Google Colab, run this in the first cell and everything should be set up for you to import and use
!pip3 install torch===1.2.0 torchvision===0.4.0 -f https://download.pytorch.org/whl/torch_stable.html
!pip install typeguard
!git clone https://github.com/fastai/fastai_dev.git
%cd fastai_dev/dev