<!--- Verify first that your issue is not already reported on GitHub -->
<!--- Also test if the latest release and devel branch are affected too -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### 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

- Id or Full path of parent group in the form of group/name
    version_added: "2.8"
    type: str
  visibility:
    description:
      - Default visibility of the group
    version_added: "2.8"
    choices: ["private", "internal", "public"]
    default: private
    type: str
'''
EXAMPLES = '''
- name: "Delete GitLab Group"
  gitlab_group:
    api_url: https://gitlab.example.com/
    api_token: "{{ access_token }}"
    validate_certs: False
    name: my_first_group
    state: absent
- name: "Create GitLab Group"
  gitlab_group:
    api_url: https://gitlab.example.com/
    validate_certs: True
    api_username: dj-wasabi
    api_password: "MySecretPassword"
    name: my_first_group
    path: my_first_group
    state: present
# The group will by created at https://gitlab.dj-wasabi.local/super_parent/parent/my_first_group
- name: "Create GitLab SubGroup"