Suggest replacements of SHA-1 intermediate certs with known SHA-2 certs

So as more information becomes available from issue#24 we can add more certs to the `fingerprints.json` file.

Essentially think this works but @konklone should probably go over the code. Also I've added a simple check to only run the `.sha2URL` method when we aren't looking at a root certificate. Could probably make that check step even better as we wouldn't need to run the method on the site's actual certificate.
Right, worked out the issue, I'm not sure how JSON deals with HTML, but their site is crap at it. In the URL as its saved in the `.json` file, there are two instances of `&amp;`. In the URL field in your browser just swap the `&amp;`s for `&`s and we should be golden :)