test_s3: add versioned multipart upload test

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
s3test: test copy version

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
test: fixes

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
s3test: add versioned multi delete

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
s3test: add a new multi obj delete test

Validate creation of delete marker.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>