Modified the Toolbar code to match the articles

On the same PR I modified examples for some
earlier articles and modified the repo to match

Author: Seth Lemmons

03-defining-classes/a-functional-basic/package-lock.json

@@ -13,4 +13,4 @@
     "test": "react-scripts test --env=jsdom",
     "eject": "react-scripts eject"
   }
-}
+}

03-defining-classes/a-functional-basic/package.json

@@ -1,16 +1,5 @@
-import React, { Component } from 'react';
-import './App.css';
-
+import React from 'react';
 import MyComponent from './MyComponent'
+import './App.css';
 
-class App extends Component {
-  render() {
-    return (
-      <div className="App">
-        <MyComponent/>
-      </div>
-    );
-  }
-}
-
-export default App;
+export default () => <MyComponent />;