I think columns need correction for GridColumn interface:
interface GridColumn { aggregates?: any; attributes?: any; columns?: any; //I think this should be GridColumn[] not any command?: GridColumnCommandItem[]; encoded?: boolean; field?: string; filterable?: boolean|GridColumnFilterable; footerAttributes?: any; footerTemplate?: string|Function; format?: string; groupable?: boolean; groupHeaderTemplate?: string|Function; groupFooterTemplate?: string|Function; headerAttributes?: any; headerTemplate?: string|Function; hidden?: boolean; locked?: boolean; lockable?: boolean; minScreenWidth?: number; sortable?: boolean|GridColumnSortable; template?: string|Function; title?: string; width?: string|number; values?: any; menu?: boolean; }