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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

changed = False
        for arg_key, arg_value in arguments.items():
            if arguments[arg_key] is not None:
                if getattr(group, arg_key) != arguments[arg_key]:
                    setattr(group, arg_key, arguments[arg_key])
                    changed = True
        return (changed, group)
    def deleteGroup(self):
        group = self.groupObject
        if len(group.projects.list()) >= 1:
            self._module.fail_json(
                msg="There are still projects in this group. These needs to be moved or deleted before this group can be removed.")
        else:
            if self._module.check_mode:
                return True
            try:
                group.delete()
            except Exception as e:
                self._module.fail_json(msg="Failed to delete group: %s " % to_native(e))
    '''
    @param name Name of the groupe
    @param full_path Complete path of the Group including parent group path. <parent_path>/<group_path>
    '''
    def existsGroup(self, project_identifier):