Add an option to setup a CI configuration

[Maximilien-R]

In order to improve the developer experience it could be nice to add an option to the Cookiecutter template to setup a CI configuration which should be compliant with the gazr specification.

This could be through Travis-CI or Github Actions (the best would be to let the choice to the end user).

The cookiecutter variable could be something like:

{
  "setup_ci": ["None", "Github Actions", "Travis-CI"]
}