For backward compatibility (and easier to use in the common case of a single URL) it'd be great to leave the Url config option and add Urls as a separate alternative. Also, and this is nit-picky, Go's idiom (which we've been pretty good at using in Heka, modulo the AMQP plugins) is to camel case var names, where even acronyms only have the first letter capitalized. Would appreciate use of `Urls` instead of `URLs`.