SIP-32: Moving frontend code to the base of the repo (#9098)

* move assets out, get webpack dev working

* update docs to reference superset-frontend

* draw the rest of the owl

* fix docs

* fix webpack script

* rats

* correct docs

* fix tox dox

superset-frontend/spec/javascripts/welcome/Welcome_spec.jsx

@@ -0,0 +1,36 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import React from 'react';
+import { Panel, Row, Tab } from 'react-bootstrap';
+import { shallow } from 'enzyme';
+
+import Welcome from '../../../src/welcome/Welcome';
+
+describe('Welcome', () => {
+  const mockedProps = {};
+  it('is valid', () => {
+    expect(React.isValidElement(<Welcome {...mockedProps} />)).toBe(true);
+  });
+  it('renders 4 Tab, Panel, and Row components', () => {
+    const wrapper = shallow(<Welcome {...mockedProps} />);
+    expect(wrapper.find(Tab)).toHaveLength(3);
+    expect(wrapper.find(Panel)).toHaveLength(3);
+    expect(wrapper.find(Row)).toHaveLength(3);
+  });
+});