Expand bit.ly

[Sjors]

This may be a bit of scope creep, because afaik bit.ly is not used by Twitter itself (see #36), but rather by some users of it. Probably automatic social media cross-posting tools.

However, I'm assuming it's easy to just add it to the list of shorteners that are expanded.

[timhutton]

@Sjors As I think you realized on the other thread, we don't expand any of these short-form URLs using internet requests. The archive JSON tells us the expansion for the t.co shorteners, that's all.

I can see that expanding shorteners is something that we could be doing, and would be beneficial but it's a much wider problem than this project and may be better tackled by a different tool.

[Sjors]

It could indeed be handled with a separate tool, if #42 doesn't make it.