Boto library is changed, so an example need to be updated.
- Change boto.s3.Connection to boto.s3.connection.S3Connection, it's the
right syntax.
- Remove calling_format arg, is unnecessary and in some cases, it doesn't
works. Default calling_format(DefaultCallingFormat) worked fine.
- Update an example client using boto3 library.
- Note libraries version.
Change-Id: If02edd337e451aff257fa9db920f2bfbf230d924
Closes-Bug: #1660387