* 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
* Move to the python:alpine docker image
- Switch the base images for local and production to alpine
- Install extra dependencies for psycopg2, Pillow and cffi
- Change shebang for shell scripts to use sh instead of bash
* Move to the python:alpine docker image
- Migrate group and user creation to Alpine syntax
* Move to the python:alpine docker image
- Remove `function` keyword, unsupported in shell
* Upgrade various places to the latest Python 3.6
* Test support for translations
* Add gettext library, required for translations support
* Add locale folder for translations support with README documenting it
* Update Changelog
* Tweak command to test translations support
