def add_user_to_group(group, role, email):
    """Add a user to a group the caller owns

    Args:
        group (str): Group name
        role (str) : Role of user for group; either 'member' or 'admin'
        email (str): Email of user or group to add
    
    Swagger:
        https://api.firecloud.org/#!/Groups/addUserToGroup
    """
    uri = "groups/{0}/{1}/{2}".format(group, role, email)
    return __put(uri)