Add TRED.com to the showcase page

Summary:
Thanks for submitting a pull request! Please provide enough information so that others can review your pull request:

> **Unless you are a React Native release maintainer and cherry-picking an *existing* commit into a current release, ensure your pull request is targeting the `master` React Native branch.**

(You can skip this if you're fixing a typo or adding an app to the Showcase.)

Explain the **motivation** for making this change. What existing problem does the pull request solve?

Prefer **small pull requests**. These are much easier to review and more likely to get merged. Make sure the PR does only one thing, otherwise please split it.

**Test plan (required)**

Demonstrate the code is solid. Example: The exact commands you ran and their output, screenshots / videos if the pull request changes UI.

Make sure tests pass on both Travis and Circle CI.

**Code formatting**

Look around. Match the style of the rest of the codebase. See also the simple [style guide](https://github.com/face
Closes https://github.com/facebook/react-native/pull/9175

Differential Revision: D3658765

Pulled By: hramos

fbshipit-source-id: bc8a37fdd6393a2107b33c9fd1b8620cb5a7c07c

website/src/react-native/showcase.js

@@ -126,6 +126,14 @@ var featured = [
     infoLink: 'https://techcrunch.com/2016/02/01/refinery29-debuts-its-first-app-a-morning-news-round-up-called-refinery29-am/',
     infoTitle: 'Refinery29 debuts its first app',
   },
+  {
+    name: 'TRED - Sell your car for more',
+    icon: 'http://a1.mzstatic.com/us/r30/Purple20/v4/b0/0c/07/b00c07d2-a057-06bc-6044-9fdab97f370f/icon175x175.jpeg',
+    linkAppStore:  'https://itunes.apple.com/us/app/tred-sell-my-car-for-more!/id1070071394?mt=8',
+    linkPlayStore:  'https://play.google.com/store/apps/details?id=com.tredmobile&hl=en',
+    infoLink: 'http://www.geekwire.com/2015/mobile-dealership-tred-raises-another-1m-to-help-used-car-owners-make-more-money/',
+    infoTitle: 'Sell your car for thousands more than Craigslist or the dealer with TRED',
+  },
   {
     name: 'Bitt Wallet',
     icon: 'http://a4.mzstatic.com/us/r30/Purple69/v4/5b/00/34/5b003497-cc85-a0d0-0d3e-4fb3bc6f95cd/icon175x175.jpeg',