feat: implement #184: add support for the 'default:' node

        # Parse variables node

        if 'variables' in data:

            GitLab.__global_variables(data['variables'], global_values)

            GitLab.__globals_variables(data['variables'], global_values)

        # Parse default node

        if 'default' in data:

            # Parse default image node

            if 'image' in data['default']:

                if 'image' in data:

                    raise SyntaxError(

                        'image is defined in top-level and `default:` entry')

                GitLab.__globals_image(data['default']['image'], global_values)

            # Parse default before_script node

            if 'before_script' in data['default']:

                if 'before_script' in data:

                    raise SyntaxError(

                        'before_script is defined in top-level and `default:` entry')

                global_values['before_script'] = GitLab.__scripts(

                    data['default']['before_script'])

            # Parse default after_script node

            if 'after_script' in data['default']:

                if 'after_script' in data:

                    raise SyntaxError(

                        'after_script is defined in top-level and `default:` entry')

                global_values['after_script'] = GitLab.__scripts(

                    data['default']['after_script'])

            # Parse default services node

            if 'services' in data['default'] and isinstance(data['default']['services'],

                                                            list):

                if 'services' in data:

                    raise SyntaxError(

                        'services is defined in top-level and `default:` entry')

                GitLab.__globals_services(data['default']['services'], global_values)

    # Globals image

    @staticmethod

include:

  - local: '/default.yml'

stages:

  - default

after_script:

  - echo '__AFTER__'

'Job 1':

  stage: default

  script:

    - echo 'Job 1'

include:

  - local: '/default.yml'

stages:

  - default

before_script:

  - echo '__BEFORE__'

'Job 1':

  stage: default

  script:

    - echo 'Job 1'

include:

  - local: '/default.yml'

stages:

  - default

image: local

'Job 1':

  stage: default

  script:

    - echo 'Job 1'

include:

  - local: '/default.yml'

services:

  - docker:dind

stages:

  - default

'Job 1':

  stage: default

  script:

    - echo 'Job 1'