Add appveyor.yml and add an image link to the README.

The SVG image URL must be replaced by the one of the owner the
ruby-concurrency account,

Author: larskanis

README.md

@@ -1,5 +1,5 @@
 # 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) [![Code Climate](https://codeclimate.com/github/ruby-concurrency/concurrent-ruby.svg)](https://codeclimate.com/github/ruby-concurrency/concurrent-ruby) [![Inline docs](http://inch-ci.org/github/ruby-concurrency/concurrent-ruby.svg)](http://inch-ci.org/github/ruby-concurrency/concurrent-ruby) [![Dependency Status](https://gemnasium.com/ruby-concurrency/concurrent-ruby.svg)](https://gemnasium.com/ruby-concurrency/concurrent-ruby) [![License](https://img.shields.io/badge/license-MIT-green.svg)](http://opensource.org/licenses/MIT) [![Gitter chat](http://img.shields.io/badge/gitter-join%20chat%20%E2%86%92-brightgreen.svg)](https://gitter.im/ruby-concurrency/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/neq4l5toshsijdqm?svg=true)](https://ci.appveyor.com/project/ruby-concurrency/concurrent-ruby) [![Code Climate](https://codeclimate.com/github/ruby-concurrency/concurrent-ruby.svg)](https://codeclimate.com/github/ruby-concurrency/concurrent-ruby) [![Inline docs](http://inch-ci.org/github/ruby-concurrency/concurrent-ruby.svg)](http://inch-ci.org/github/ruby-concurrency/concurrent-ruby) [![Dependency Status](https://gemnasium.com/ruby-concurrency/concurrent-ruby.svg)](https://gemnasium.com/ruby-concurrency/concurrent-ruby) [![License](https://img.shields.io/badge/license-MIT-green.svg)](http://opensource.org/licenses/MIT) [![Gitter chat](http://img.shields.io/badge/gitter-join%20chat%20%E2%86%92-brightgreen.svg)](https://gitter.im/ruby-concurrency/concurrent-ruby)
 
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appveyor.yml

@@ -0,0 +1,26 @@
+install:
+  - SET PATH=C:\Ruby%ruby_version%\bin;%PATH%
+  - SET PATH=C:\MinGW\bin;%PATH%
+  - SET RAKEOPT=-rdevkit
+  - ruby --version
+  - gem --version
+  - bundle install
+
+build: off
+
+test_script:
+  - bundle exec rake ci
+
+environment:
+  matrix:
+    - ruby_version: "193"
+    - ruby_version: "200"
+#    - ruby_version: "200-x64"
+#    - ruby_version: "21"
+#    - ruby_version: "21-x64"
+#    - ruby_version: "22"
+    - ruby_version: "22-x64"
+
+matrix:
+  allow_failures:
+    - ruby_version: "193"