This commit removes the usage of MockAmazonS3 in S3BlobStoreRepositoryTests
and replaces it by a HttpServer that emulates the S3 service. This allows the
repository tests to use the real Amazon's S3 client under the hood in tests and will
allow to test the behavior of the snapshot/restore feature for S3 repositories by
simulating random server-side internal errors.
The HTTP server used to emulate the S3 service is intentionally simple and minimal
to keep things understandable and maintainable. Testing full client options on the
server side (like authentication, chunked encoding etc) remains the responsibility
of the AmazonS3Fixture.
b526309fbd