Reuse script to install gems

Author: David Rodríguez

Rakefile

@@ -152,7 +152,7 @@ namespace :no_active_record do
         sh "bundle exec rails new #{example_app_dir} --skip-active-record --skip-javascript --skip-sprockets --skip-git --skip-test-unit --skip-bundle --template=example_app_generator/generate_app.rb"
 
         in_example_app(:app_dir => example_app_dir) do
-          sh "bundle install --gemfile ./Gemfile --path ../../../bundle"
+          sh "./travis_retry_bundle_install.sh 2>&1"
           # Rails 4 cannot use a `rails` binstub generated by Bundler
           sh "bundle binstubs rspec-core rake --force"
           sh "bundle binstubs railties" unless File.exist?("bin/rails")