Added support for adding react-router and examples

Author: jwbennet

packages/react-scripts/template/src/App.js

@@ -0,0 +1,63 @@
+import React, { Component } from 'react';
+{% if router -%}
+import { HashRouter as Router, Link, Route } from 'react-router-dom';
+{%- endif %}
+
+import logo from './logo.svg';
+import './App.css';
+{% if redux -%}
+import IncrementButton from './containers/IncrementButton';
+{%- endif %}
+
+{% if router -%}
+const Home = () => (
+    <div>
+        <h3>Home</h3>
+        {% if redux -%}
+        <IncrementButton />
+        {%- endif %}
+    </div>
+);
+const Foo = () => (
+    <h3>Foo</h3>
+);
+const Bar = () => (
+    <h3>Bar</h3>
+);
+const Baz = () => (
+    <h3>Baz</h3>
+);
+{%- endif %}
+
+class App extends Component {
+  render() {
+    return (
+      {% if router -%}
+      <Router>
+      {%- endif %}
+      <div className="App">
+        <div className="App-header">
+          <img src={logo} className="App-logo" alt="logo" />
+          <h2>Welcome to React</h2>
+        </div>
+        <p className="App-intro">
+          To get started, edit <code>src/App.js</code> and save to reload.
+        </p>
+        {% if router -%}
+        <Link to="/" replace>Home</Link> | <Link to="/foo" replace>Foo</Link> | <Link to="/bar" replace>Bar</Link> | <Link to="/baz" replace>Baz</Link>
+        <Route exact path="/" component={Home} />
+        <Route path="/foo" component={Foo} />
+        <Route path="/bar" component={Bar} />
+        <Route path="/baz" component={Baz} />
+        {%- elif redux -%}
+        <IncrementButton />
+        {%- endif %}
+      </div>
+      {% if router -%}
+      </Router>
+      {%- endif %}
+    );
+  }
+}
+
+export default App;

packages/react-scripts/template/src/App.js.j2

@@ -1,8 +1,16 @@
 'use strict';
 
-module.exports = (currentDependencies, { bootstrap, fontawesome, redux }) => {
+module.exports = (currentDependencies, { bootstrap, fontawesome, redux, router }) => {
   const boostrapDependencies = bootstrap ? { "bootstrap": "3.3.7", "react-bootstrap": "0.31.0" } : {};
   const fontawesomeDependencies = fontawesome ? { "font-awesome": "4.7.0", "react-fontawesome": "1.6.1" } : {};
   const reduxDependencies = redux ? { "redux": "3.6.0", "redux-thunk": "2.2.0", "redux-promise": "0.5.3", "redux-logger": "3.0.1", "redux-actions": "2.0.2", "react-redux": "5.0.4" } : {};
-  return Object.assign({}, currentDependencies, boostrapDependencies, fontawesomeDependencies, reduxDependencies);
+  const routerDependencies = router ? { "react-router-dom": "4.1.1" } : {};
+  return Object.assign(
+    {},
+    currentDependencies,
+    boostrapDependencies,
+    fontawesomeDependencies,
+    reduxDependencies,
+    routerDependencies
+  );
 }