## Description
Following up on @webyneter attempt in #1205, which is now getting outdated, I've tried to make Gulp task runner work with Docker. There is no documentation yet, but this seems to work locally with the custom bootstrap compilation...
- [x] Add a node image for local developement
- [x] Proxy the django image rather than localhost in Browser sync, pass header to keep hostname
- [x] Don't call the runserver command from Gulp, let docker-compose handle
- [x] Update package.json & gulpfile.js templates to reduce the number of unwanted empty lines
- [x] Use [multi-stage build](https://docs.docker.com/develop/develop-images/multistage-build/) in production to make sure the static assets are produced
- [x] Update documentation
- [x] Verify that the previous issue with static assets missing from production isn't there
## Rationale
Currently, the static build isn't working nicely with Docker, extra manual setup is required.
Fixes#1762
## Description
Replace Caddy with Traefik
## Rationale
There is some trouble with the Caddy license (https://github.com/pydanny/cookiecutter-django/pull/1282#issuecomment-329617536)
@drdaeman suggested using Traefik (https://github.com/pydanny/cookiecutter-django/pull/1282#issuecomment-353655273) which supports ACME and also plays very nice with Docker.
## Comments
I am currently using the proposed setup on a live site and it working great so far. If this PR is of interest to the maintainers, then I could commit more changes and take care of the documentation. Of course, any suggestions by the more experienced people around here, are welcome!
* Create a test matrix on Travis CI to help testing multiple options
* Change test_docker.sh to fail if any command in it fails
* Run black on the CI with --check option
* Fix formatting of project files using black
* Install black in the docker container
* Exclude migrations in black checks
* Fix Black formatting violations
* Run black on the whole generated project & fix issues
