Add support for rspec-3.3

[fix #345]

mutant-rspec.gemspec

@@ -18,7 +18,7 @@ Gem::Specification.new do |gem|
   gem.extra_rdoc_files = %w[TODO LICENSE]
 
   gem.add_runtime_dependency('mutant', "~> #{gem.version}")
-  gem.add_runtime_dependency('rspec-core', '>= 3.0.0', '< 3.3.0')
+  gem.add_runtime_dependency('rspec-core', '>= 3.0.0', '< 3.4.0')
 
   gem.add_development_dependency('bundler', '~> 1.3', '>= 1.3.5')
 end

spec/integration/mutant/rspec_spec.rb

@@ -2,21 +2,11 @@ RSpec.describe 'rspec integration', mutant: false do
 
   let(:base_cmd) { 'bundle exec mutant -I lib --require test_app --use rspec' }
 
-  context 'RSpec 3.0' do
-    let(:gemfile) { 'Gemfile.rspec3.0' }
+  %w[3.0 3.1 3.2 3.3].each do |version|
+    context "RSpec #{version}" do
+      let(:gemfile) { "Gemfile.rspec#{version}" }
 
-    it_behaves_like 'framework integration'
-  end
-
-  context 'RSpec 3.1' do
-    let(:gemfile) { 'Gemfile.rspec3.1' }
-
-    it_behaves_like 'framework integration'
-  end
-
-  context 'RSpec 3.2' do
-    let(:gemfile) { 'Gemfile.rspec3.2' }
-
-    it_behaves_like 'framework integration'
+      it_behaves_like 'framework integration'
+    end
   end
 end

test_app/Gemfile.rspec3.3

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+gem 'rspec',      '~> 3.3.0'
+gem 'rspec-core', '~> 3.3.0'
+gem 'mutant',       path: '../'
+gem 'mutant-rspec', path: '../'
+gem 'adamantium'