Add Coveralls for code coverage reporting

Gemfile

@@ -17,6 +17,7 @@ group :development do
 end
 
 group :test do
+  gem 'coveralls'
   gem 'rack-test'
   gem 'rspec', '>= 2.11'
   gem 'simplecov', :require => false

README.md

@@ -1,13 +1,17 @@
 # OmniAuth: Standardized Multi-Provider Authentication
+
 [![Gem Version](https://badge.fury.io/rb/omniauth.png)][gem]
 [![CI Build Status](https://secure.travis-ci.org/intridea/omniauth.png?branch=master)][travis]
 [![Dependency Status](https://gemnasium.com/intridea/omniauth.png?travis)][gemnasium]
 [![Code Climate](https://codeclimate.com/github/intridea/omniauth.png)][codeclimate]
+[![Coverage Status](https://coveralls.io/repos/intridea/omniauth/badge.png?branch=master)][coveralls]
+
 
 [gem]: https://rubygems.org/gems/omniauth
 [travis]: http://travis-ci.org/intridea/omniauth
 [gemnasium]: https://gemnasium.com/intridea/omniauth
 [codeclimate]: https://codeclimate.com/github/intridea/omniauth
+[coveralls]: https://coveralls.io/r/intridea/omniauth
 
 **OmniAuth 1.0 has several breaking changes from version 0.x. You can set
 the dependency to `~> 0.3.2` if you do not wish to make the more difficult

spec/helper.rb

@@ -1,9 +1,11 @@
-unless ENV['CI']
-  require 'simplecov'
-  SimpleCov.start do
-    add_filter 'spec'
-  end
-end
+require 'simplecov'
+require 'coveralls'
+
+SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
+  SimpleCov::Formatter::HTMLFormatter,
+  Coveralls::SimpleCov::Formatter
+]
+SimpleCov.start
 
 require 'rspec'
 require 'rack/test'