Example/add high order component example (#2331)

* temporary commit

* update code

* completed example higher order component

* remove custom server

examples/with-higher-order-component/README.md

+[![Deploy to now](https://deploy.now.sh/static/button.svg)](https://deploy.now.sh/?repo=https://github.com/zeit/next.js/tree/master/examples/with-higher-order-component)
+
+# Higher Order Component example
+
+## How to use
+
+Download the example [or clone the repo](https://github.com/zeit/next.js):
+
+Install it and run:
+
+**npm**
+```bash
+npm install
+npm run dev
+```
+
+**yarn**
+```bash
+npm install
+npm run dev
+```
+
+Deploy it to the cloud with [now](https://zeit.co/now) ([download](https://zeit.co/download))
+
+```bash
+now
+```
+
+## About example
+
+This example show you how to create Higher Order Component in next.js

examples/with-higher-order-component/components/withApp.js

+import React from 'react'
+
+function withApp (Child) {
+  return class WrappedComponent extends React.Component {
+    static getInitialProps (context) {
+      return Child.getInitialProps(context)
+    }
+    render () {
+      return (
+        <div>
+          <header>
+            <h1>Header</h1>
+          </header>
+          <main>
+            <Child greeting='Hello From HOC' {...this.props} />
+          </main>
+          <footer>
+            <h1>Footer</h1>
+          </footer>
+        </div>
+      )
+    }
+  }
+}
+
+export default withApp

examples/with-higher-order-component/package.json

+{
+  "name": "with-higher-order-component",
+  "version": "1.0.0",
+  "scripts": {
+    "dev": "next",
+    "build": "next build",
+    "start": "next start"
+  },
+  "dependencies": {
+    "next": "latest",
+    "react": "^15.4.2",
+    "react-dom": "^15.4.2"
+  },
+  "author": "",
+  "license": "ISC"
+}

examples/with-higher-order-component/pages/index.js

+import React from 'react'
+import withApp from '../components/withApp'
+
+class Index extends React.Component {
+  static getInitialProps (context) {
+    const { isServer } = context
+    return { isServer }
+  }
+  render () {
+    const { greeting } = this.props
+    return (
+      <div>
+        <h2>Index page</h2>
+        <h3 style={{ color: 'red' }}>{greeting}</h3>
+      </div>
+    )
+  }
+}
+
+export default withApp(Index)