FollowRedirects should disregard content headers

[stevelacey]

FollowRedirects was failing with a ReadTimeout for me, the reason turned out to be because the request I was doing was a multipart post which naturally has a form multipart Content-Type and a long Content-Length for the post body.

When this request is convert to a GET as per standards_compliance: false these headers should probably be disregarded by default, the POST body is not coming along for the ride so these are definitely going to be wrong.

To achieve this myself I had to use the callback option:

f.use FaradayMiddleware::FollowRedirects, callback: lambda { |response, redirect|
  redirect.request_headers.delete("Content-Length")
  redirect.request_headers.delete("Content-Type")
}

[iMacTia]

Thanks @stevelacey, that makes sense and it would make the middleware smarter.
I won't be able to work on this right now, but hopefully there will be takers ❤️ .