Add coverage tools

Gemfile

@@ -3,4 +3,6 @@ source 'https://rubygems.org'
 # Specify gem dependencies in active_model_serializers.gemspec
 gemspec
 
-gem "sqlite3"
+gem 'sqlite3'
+gem 'coveralls', :require => false
+gem 'simplecov', :require => false

test/coverage_setup.rb

@@ -0,0 +1,12 @@
+require 'simplecov'
+require 'coveralls'
+
+SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
+  SimpleCov::Formatter::HTMLFormatter,
+  Coveralls::SimpleCov::Formatter
+]
+
+SimpleCov.start do
+  add_group "lib", "lib"
+  add_group "test", "test"
+end

test/test_helper.rb

@@ -1,4 +1,5 @@
 require 'bundler/setup'
+require 'coverage_setup'
 require 'test/unit'
 require 'active_model_serializers'
 require 'fixtures/poro'