Avoid Package Overwrite about simplepypi HOT 1 OPEN

Hi @lovato - this was actually intentional. The way we were using simplepypi at work we would sometimes need to re-submit a patched package with the same version number as the unpatched one, and we wanted simplepypi to silently overwrite the old package.

However, I can see why other people would not want that to be the case. If someone wanted to submit a pull request that supported 1) deleting a package and 2) have simplepypi return some sort of sane error when you try to resubmit a package with the same name / version, I think that'd be reasonable way to support both use cases.

from simplepypi.