[Feature] Docker image

[titouanmathis]

This PR adds a Docker image with advanced support for testing .htaccess files before deploying them:

# Create your .htaccess file with redirections to test
vim .htaccess

# Create a CSV fiels containing from,to URLS
vim redirects.csv

# Configure the temporary hosts referenced in your redirects, they will be configured in the Docker container
export DOMAINS='fqdn.com,www.fqdn.com'

# Run the Docker image by linking the current directy to /app
docker run -it --rm -v $PWD:/app -e DOMAINS studiometa/cli-test-redirection redirects.csv