AlertBox and MaintenanceBanner: remove deprecated components (#902)

* remove files/refs

* remove problem refs

* try skipping test

* Revert "remove problem refs"

This reverts commit d13a060.

* Revert "try skipping test"

This reverts commit df71492.

packages/design-system-dashboard-cli/coverage/lcov-report/write-react-owners-to-csv.js.html

@@ -330,14 +330,13 @@ <h1><a href="index.html">All files</a> write-react-owners-to-csv.js</h1>
 const today = require('./today');
 &nbsp;
 const componentsToKeep = [
-  'AlertBox',
   'ExpandingGroup',
   'IconSearch',
   'LoadingIndicator',
   'TextInput',
 ];
 &nbsp;
-const hasMigrationScript = ['AlertBox', 'LoadingIndicator'];
+const hasMigrationScript = ['LoadingIndicator'];
 &nbsp;
 function cleanPath(pathToClean) {
   const cwd = process.cwd();

packages/react-components/index.js

@@ -1,24 +1,19 @@
-import AlertBox, { ALERT_TYPE } from './AlertBox';
 import Breadcrumbs from './Breadcrumbs';
 import ExpandingGroup from './ExpandingGroup';
 import IconBase from './IconBase';
 import IconSearch from './IconSearch';
 import LoadingIndicator from './LoadingIndicator';
-import MaintenanceBanner from './MaintenanceBanner';
 import Modal from './Modal';
 import TextInput from './TextInput';
 
 import './i18n-setup';
 
 export {
-  AlertBox,
-  ALERT_TYPE,
   Breadcrumbs,
   ExpandingGroup,
   IconBase,
   IconSearch,
   LoadingIndicator,
-  MaintenanceBanner,
   Modal,
   TextInput,
 };