new post on resque, retrying, and idempotence

A reaction to [this post](http://eng.joingrouper.com/blog/2014/06/27/too-many-signals-resque-on-heroku/), where they have the same problem as us, but, in my opinion, solved it the wrong way.

This is bit technical but hopefully in the "this team knows its shit" category.
@davetron5000 No problem with this reference. In the line below, instead of saying "we charge our clients money via a third party," can we say something along the lines of "secure third party billing app Braintree"? I don't want a client who doesn't understand this to read it and think we're all willy-nilly double charging people.