Add/Update Badges on README

Author: mptap

README.md

@@ -1,5 +1,9 @@
+![SendGrid Logo](https://uiux.s3.amazonaws.com/2016-logos/email-logo%402x.png)
 [![Travis Badge](https://travis-ci.org/sendgrid/sendgrid-java.svg?branch=master)](https://travis-ci.org/sendgrid/sendgrid-java)
 [![Email Notifications Badge](https://dx.sendgrid.com/badge/java)](https://dx.sendgrid.com/newsletter/java)
+[![Twitter Follow](https://img.shields.io/twitter/follow/sendgrid.svg?style=social&label=Follow)](https://twitter.com/sendgrid)
+[![GitHub contributors](https://img.shields.io/github/contributors/sendgrid/sendgrid-java.svg)](https://github.com/sendgrid/sendgrid-java/graphs/contributors)
+[![MIT licensed](https://img.shields.io/badge/license-MIT-blue.svg)](./LICENSE.txt)
 
 **NEW:** Subscribe to email [notifications](https://dx.sendgrid.com/newsletter/java) for releases and breaking changes.
 
@@ -24,6 +28,7 @@ We appreciate your continued support, thank you!
 * [How to Contribute](#contribute)
 * [Troubleshooting](#troubleshooting)
 * [About](#about)
+* [License](#license)
 
 <a name="installation"></a>
 # Installation
@@ -221,4 +226,5 @@ sendgrid-java is guided and supported by the SendGrid [Developer Experience Team
 
 sendgrid-java is maintained and funded by SendGrid, Inc. The names and logos for sendgrid-java are trademarks of SendGrid, Inc.
 
-![SendGrid Logo](https://uiux.s3.amazonaws.com/2016-logos/email-logo%402x.png)
+# License
+[The MIT License (MIT)](LICENSE.txt)