Travis CI for development and production docker images.

Fix errors in .travis.yml.

Travis CI for Docker.

Dockerize the Flask application.

Test the production docker image.

Add the missing environment variables in the systemd unit file.

Add the steps for deploying pytwask in the cloud.

Fix the encrypted PyPI password in .travis.yml again.

Connect to Redis via UNIX domain socket.

Complete the documentation and use Travis for CI.