Dockerize QANet in a GPU enabled container

Changes made

Add Dockerfile to run QANet in a GPU enabled container
Add bottle python package to requirements.txt
Change SQuAD & Glove download destination directory in download.sh for easier Docker volume mapping
Comment out python3 -m spacy download en in download.sh (throws error since only python 2.7 spacy is installed)
Change source directory for SQuAD and Glove data files in config.py to reflect changes in download.sh
Add Docker commands to README.md

localminimum / QANet