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##### SUMMARY
<!--- Explain the problem briefly below -->

`python-gitlab` library release a new version [v1.13.0](https://github.com/python-gitlab/python-gitlab/releases/tag/v1.13.0). User/Password authentication as been removed completely causing all Ansible GitLab module to fail... 

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->

gitlab_group
gitlab_deploy_key
gitlab_hook
gitlab_project
gitlab_project_variable
gitlab_runner
gitlab_user

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
All versions

state: absent
  delegate_to: localhost
- name: Create GitLab Project in group Ansible
  gitlab_project:
    api_url: https://gitlab.example.com/
    validate_certs: True
    api_username: dj-wasabi
    api_password: "MySecretPassword"
    name: my_first_project
    group: ansible
    issues_enabled: False
    wiki_enabled: True
    snippets_enabled: True
    import_url: http://git.example.com/example/lab.git
    state: present
  delegate_to: localhost
'''
RETURN = '''
msg:
  description: Success or failure message
  returned: always
  type: str
  sample: "Success"
result:
  description: json parsed response from the server
  returned: always
  type: dict
error:
  description: the error message returned by the GitLab API
  returned: failed