Dashboard refactory (#3581)

Create Chart component for all chart fetching and rendering, and apply redux architecture in dashboard view.

superset/assets/javascripts/dashboard/components/DashboardAlert.jsx

@@ -0,0 +1,21 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import { Alert } from 'react-bootstrap';
+
+const propTypes = {
+  alertContent: PropTypes.node.isRequired,
+};
+
+const DashboardAlert = ({ alertContent }) => (
+  <div id="alert-container">
+    <div className="container-fluid">
+      <Alert bsStyle="warning">
+        {alertContent}
+      </Alert>
+    </div>
+  </div>
+);
+
+DashboardAlert.propTypes = propTypes;
+
+export default DashboardAlert;