Add gitlab.yml for linting and testing

# https://git.drupalcode.org/project/gitlab_templates/

variables:
  # There is currently only compiled CSS files in the module.
  SKIP_STYLELINT: "1"

include:
  - project: $_GITLAB_TEMPLATES_REPO
    ref: $_GITLAB_TEMPLATES_REF
    file:
      - '/includes/include.drupalci.main.yml'
      - '/includes/include.drupalci.variables.yml'
      - '/includes/include.drupalci.workflows.yml'