Grant a role in a project/domain to a user/group

    CLI Example:

    .. code-block:: bash

        salt '*' keystoneng.role_grant name=role1 user=user1 project=project1
        salt '*' keystoneng.role_grant name=ddbe3e0ed74e4c7f8027bad4af03339d group=user1 project=project1 domain=domain1
        salt '*' keystoneng.role_grant name=ddbe3e0ed74e4c7f8027bad4af03339d group=19573afd5e4241d8b65c42215bae9704 project=1dcac318a83b4610b7a7f7ba01465548

def role_grant(auth=None, **kwargs):
    '''
    Grant a role in a project/domain to a user/group

    CLI Example:

    .. code-block:: bash

        salt '*' keystoneng.role_grant name=role1 user=user1 project=project1
        salt '*' keystoneng.role_grant name=ddbe3e0ed74e4c7f8027bad4af03339d group=user1 project=project1 domain=domain1
        salt '*' keystoneng.role_grant name=ddbe3e0ed74e4c7f8027bad4af03339d group=19573afd5e4241d8b65c42215bae9704 project=1dcac318a83b4610b7a7f7ba01465548
    '''
    cloud = get_operator_cloud(auth)
    kwargs = _clean_kwargs(**kwargs)
    return cloud.grant_role(**kwargs)