Add a docker builder for production env

Usage:

1. Edit docker-build/uwsgi.ini according to your design;
2. Run in project directory.
3. Get done.

Notes:

1. canaille config file placed at /etc/canaille/config.toml, so, a mapping is required while run the docker image.
2. access your_host:5000 (or according to your modification of docker-build/uwsgi.ini) to get touch with canaille, enjoy!