For the most part, our existing GridFS integration tests only touch the open_upload_stream() and open_download_stream() bucket methods. We should add basic integration tests for the remaining bucket methods:

• bucket::open_upload_stream_with_id()
• bucket::upload_from_stream()
• bucket::upload_from_stream_with_id()
• bucket::download_to_stream()
• bucket::delete_file()
• bucket::find()