RECAP Fails on Audio Files

[mlissner]

At least some of the time, PACER embeds mp3 files in PDFs for the public to download. That's weird, but it's nice because it means that RECAP will probably work for them pretty easily. The problem I think we run into is that this section of code fails:

https://github.com/freelawproject/recap-chrome/blob/bed0e7e4b243e136fc103f01cb4d683208f4e1d7/content_delegate.js#L243-L249

It fails because the receipt page looks like:

Usually, it says Image85-0 instead of AUDIO85-0. It's possible that this will work fine, but these are pretty big files, which may cause other issues (see #235).