Make Welcome page into a simple React app (#4147)

* Make Welcome page into a simple React app

This removes a dependency on datatables, we should be able to get rid
of it as we re-write the Table and PivotTable viz

* tests/lint

* Bump node version to latest

superset/assets/javascripts/welcome/DashboardTable.jsx

@@ -0,0 +1,71 @@
+/* eslint no-unused-vars: 0 */
+import React from 'react';
+import ReactDOM from 'react-dom';
+import PropTypes from 'prop-types';
+import { Table, Tr, Td, Thead, Th, unsafe } from 'reactable';
+
+import '../../stylesheets/reactable-pagination.css';
+
+const $ = window.$ = require('jquery');
+
+const propTypes = {
+  search: PropTypes.string,
+};
+
+export default class DashboardTable extends React.PureComponent {
+  constructor(props) {
+    super(props);
+    this.state = {
+      dashboards: false,
+    };
+  }
+  componentDidMount() {
+    const url = (
+      '/dashboardmodelviewasync/api/read' +
+      '?_oc_DashboardModelViewAsync=changed_on' +
+      '&_od_DashboardModelViewAsync=desc');
+    $.getJSON(url, (data) => {
+      this.setState({ dashboards: data.result });
+    });
+  }
+  render() {
+    if (this.state.dashboards) {
+      return (
+        <Table
+          className="table"
+          sortable={['dashboard', 'creator', 'modified']}
+          filterBy={this.props.search}
+          filterable={['dashboard', 'creator']}
+          itemsPerPage={50}
+          hideFilterInput
+          columns={[
+            { key: 'dashboard', label: 'Dashboard' },
+            { key: 'creator', label: 'Creator' },
+            { key: 'modified', label: 'Modified' },
+          ]}
+          defaultSort={{ column: 'modified', direction: 'desc' }}
+        >
+          {this.state.dashboards.map(o => (
+            <Tr key={o.id}>
+              <Td column="dashboard" value={o.dashboard_title}>
+                <a href={o.url}>{o.dashboard_title}</a>
+              </Td>
+              <Td column="creator" value={o.changed_by_name}>
+                {unsafe(o.creator)}
+              </Td>
+              <Td column="modified" value={o.changed_on} className="text-muted">
+                {unsafe(o.modified)}
+              </Td>
+            </Tr>))}
+        </Table>
+      );
+    }
+    return (
+      <img
+        className="loading"
+        alt="Loading..."
+        src="/static/assets/images/loading.gif"
+      />);
+  }
+}
+DashboardTable.propTypes = propTypes;