README.md in sendgrid4r-1.8.1 vs README.md in sendgrid4r-1.10.0

- old
+ new

@@ -2,9 +2,10 @@
 
 This gem allows you to quickly and easily access to SendGrid Web API v3 for Ruby.
 See [api reference](https://sendgrid.com/docs/API_Reference/Web_API_v3/index.html) for more detail
 
 [![Build Status](https://travis-ci.org/awwa/sendgrid4r.svg?branch=master)](https://travis-ci.org/awwa/sendgrid4r)
+[![Gem Version](https://badge.fury.io/rb/sendgrid4r.svg)](https://badge.fury.io/rb/sendgrid4r)
 
 # [Documentation](https://github.com/awwa/sendgrid4r/wiki)
 
 # Contributing