<!--- 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

self.userObject = user
        if changed:
            if self._module.check_mode:
                self._module.exit_json(changed=True, msg="Successfully created or updated the user %s" % username)
            try:
                user.save()
            except Exception as e:
                self._module.fail_json(msg="Failed to update user: %s " % to_native(e))
            return True
        else:
            return False
    '''
    @param group User object
    '''
    def getUserId(self, user):
        if user is not None:
            return user.id
        return None
    '''
    @param user User object
    @param sshkey_name Name of the ssh key
    '''
    def sshKeyExists(self, user, sshkey_name):
        keyList = map(lambda k: k.title, user.keys.list())
        return sshkey_name in keyList
    '''
    @param user User object
    @param sshkey Dict containing sshkey infos {"name": "", "file": ""}
    '''
    def addSshKeyToUser(self, user, sshkey):