get rid of CURLOPT_FOLLOWLOCATION errors

According to Pete, Mailchimp doesn't actually return redirects from their API right now, making FOLLOWLOCATION unnecessary. While they work to come up with a permanent fix, the current advice is that we simply not set that option, so I removed the line.

See here for more info: https://github.com/mailchimp/mcapi2-php-examples/issues/2#issuecomment-44988859