allow to specify a region the integration testing

Fixes #1

Author: ph

README

@@ -11,5 +11,5 @@ If you want to run the integration test against a real bucket you need to pass
 your aws credentials to the test runner or declare it in your environment.
 
 ```
-AWS_ACCESS_KEY_ID=123 AWS_SECRET_ACCESS_KEY=secret AWS_LOGSTASH_TEST_BUCKET=mytest bundle exec rspec spec/integration/s3_spec.rb --tag integration
+AWS_REGION=us-east-1 AWS_ACCESS_KEY_ID=123 AWS_SECRET_ACCESS_KEY=secret AWS_LOGSTASH_TEST_BUCKET=mytest bundle exec rspec spec/integration/s3_spec.rb --tag integration
 ```

spec/integration/s3_spec.rb

@@ -13,7 +13,8 @@
 
   let!(:minimal_settings)  {  { "access_key_id" => ENV['AWS_ACCESS_KEY_ID'],
                                 "secret_access_key" => ENV['AWS_SECRET_ACCESS_KEY'],
-                                "bucket" => ENV['AWS_LOGSTASH_TEST_BUCKET'], 
+                                "bucket" => ENV['AWS_LOGSTASH_TEST_BUCKET'],
+                                "region" => ENV["AWS_REGION"] || "us-east-1",
                                 "temporary_directory" => Stud::Temporary.pathname('temporary_directory') }}
 
   let!(:s3_object) do