Test both rspec 2 and 3

.gitignore

@@ -33,6 +33,7 @@ measurements
 ## BUNDLER
 .bundle
 Gemfile.lock
+Gemfile.*.lock
 
 ## PROJECT::SPECIFIC
 /vendor

spec/integration/mutant/rspec_spec.rb

@@ -4,13 +4,17 @@ require 'spec_helper'
 
 describe Mutant, 'rspec integration' do
 
+  let(:base_cmd) { "bundle exec mutant -I lib --require test_app --use rspec" }
+
+  shared_examples_for 'rspec integration' do
     around do |example|
+      Bundler.with_clean_env do
         Dir.chdir(TestApp.root) do
+          Kernel.system("bundle install --gemfile=#{gemfile}")
           example.run
         end
       end
-
-  let(:base_cmd) { 'bundle exec mutant -I lib --require test_app --use rspec' }
+    end
 
     specify 'it allows to kill mutations' do
       expect(Kernel.system("#{base_cmd} ::TestApp::Literal#string")).to be(true)
@@ -35,4 +39,17 @@ describe Mutant, 'rspec integration' do
       cli = "#{base_cmd} ::TestApp::Literal"
       expect(Kernel.system(cli)).to be(false)
     end
+  end
+
+  context 'RSpec 2' do
+    let(:gemfile) { 'Gemfile.rspec2' }
+
+    it_behaves_like 'rspec integration'
+  end
+
+  context 'Rspec 3' do
+    let(:gemfile) { 'Gemfile.rspec3' }
+
+    it_behaves_like 'rspec integration'
+  end
 end

test_app/Gemfile.rspec2

@@ -0,0 +1 @@
+gem 'rspec', '~> 2.14.1'

test_app/Gemfile.rspec3

@@ -0,0 +1 @@
+gem 'rspec', '~> 3.0.0.beta2'