### Current behavior
When we use upload/4 method response body is not parsed, because parse_complete_multipart_upload does nothing
https://github.com/ex-aws/ex_aws_s3/blob/10c0ff5bd6af3644759ecdd7f3f15a9de35a8a4f/lib/ex_aws/s3/parsers.ex#L83
Delete current implementation of parse_complete_multipart_upload, because it does nothing rn. And rename parse_upload to parse_complete_multipart_upload
Environment
Elixir 1.9.1 (compiled with Erlang/OTP 21)
mix deps | grep hackney
Expected behavior
Response body is parsed
Proposed Solution
Right now parse_upload method parses CompleteMultipartUploadResult and is not used anywhere https://github.com/ex-aws/ex_aws_s3/blob/10c0ff5bd6af3644759ecdd7f3f15a9de35a8a4f/lib/ex_aws/s3/parsers.ex#L5
So, as I see, there is two options
&Parsers.parse_upload/1
as parser here https://github.com/ex-aws/ex_aws_s3/blob/10c0ff5bd6af3644759ecdd7f3f15a9de35a8a4f/lib/ex_aws/s3.ex#L938I will a PR with solution, that you consider right I, personally, prefer first solution.