static async fromAlterations(alterationsJson) {
        return new QnAMaker('', new Alterations(alterationsJson))
    }
Builds a QnAMaker instance from a Alterations Json.
@param {JSON} alterationsJson QnAMaker json
@returns {QnAMaker} new QnAMaker instance
@throws {exception} Throws on errors. exception object includes errCode and text.