补充Table组件缺少的columns的属性类型定义 (#2833)

* 补充Table组件缺少的columns的属性类型定义

* `columns` is required.

components/table/Table.tsx

@@ -96,6 +96,7 @@ interface TableContext {
 export default class Table extends React.Component<TableProps, any> {
   static propTypes = {
     dataSource: React.PropTypes.array,
+    columns: React.PropTypes.array.isRequired,
     prefixCls: React.PropTypes.string,
     useFixedHeader: React.PropTypes.bool,
     rowSelection: React.PropTypes.object,