echo the last fluffy link uploaded via slack

[emmatyping]

Sometimes people will post images via slack they would then like to use (e.g. for macros). It'd be nice if create had a method of echoing the fluffy url of the last image it uploaded in the channel from slack.

[jvperrin]

I've moved this to the slackbridge repo as it's the one that does the uploading to fluffy for images uploaded to slack, not ircbot.

[emmatyping]

Ah thanks!