"A new code requires a code file." issue

[cluppi]

While trying to upload a worker, I'm seeing the error below:

[Http_Exception]
http error: 400 | {"msg":"A new code requires a code file."}

[cluppi]

Narrowed it down to this issue:

http://stackoverflow.com/questions/25934128/curl-file-uploads-not-working-anymore-after-upgrade-from-php-5-5-to-5-6

I tried setting curl_setopt($this->curl, CURLOPT_SAFE_UPLOAD, false); and it fixed the issue.

[alnutile]

@cluppi is this where the fix had to go https://github.com/iron-io/iron_core_php/blob/master/src/IronCore.php#L269 ?