Add a license badge to README.md

Also, move the crates.io badge beyond the license badge to optimize the badge 
row's utility as a status dashboard as discussed in #525.

Fixes #525

Author: ssokolow

README.md

@@ -1,8 +1,9 @@
 # hyper
 
 [![Build Status](https://travis-ci.org/hyperium/hyper.svg?branch=master)](https://travis-ci.org/hyperium/hyper)
-[![crates.io](http://meritbadge.herokuapp.com/hyper)](https://crates.io/crates/hyper)
 [![Coverage Status](https://coveralls.io/repos/hyperium/hyper/badge.svg?branch=master)](https://coveralls.io/r/hyperium/hyper?branch=master)
+[![MIT licensed](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/hyperium/hyper/master/LICENSE)
+[![crates.io](http://meritbadge.herokuapp.com/hyper)](https://crates.io/crates/hyper)
 
 A Modern HTTP library for Rust.