Merge pull request #923 from ruby-concurrency/badges

Remove Travis and Appveyor badges

Author: chrisseaton

README.md

@@ -1,8 +1,6 @@
 # Concurrent Ruby
 
 [![Gem Version](https://badge.fury.io/rb/concurrent-ruby.svg)](http://badge.fury.io/rb/concurrent-ruby)
-[![Build Status](https://travis-ci.org/ruby-concurrency/concurrent-ruby.svg?branch=master)](https://travis-ci.org/ruby-concurrency/concurrent-ruby)
-[![Build status](https://ci.appveyor.com/api/projects/status/iq8aboyuu3etad4w?svg=true)](https://ci.appveyor.com/project/rubyconcurrency/concurrent-ruby)
 [![License](https://img.shields.io/badge/license-MIT-green.svg)](http://opensource.org/licenses/MIT)
 [![Gitter chat](https://img.shields.io/badge/IRC%20(gitter)-devs%20%26%20users-brightgreen.svg)](https://gitter.im/ruby-concurrency/concurrent-ruby)