Iron.io integration

I could use some feedback on an initial stab at a segment -> ironio integration

It funnels events from Segment.io into Iron.io's IronMQ, which allows for polling, pub/sub, and allows for seamless task processing with our IronWorker product.

a new queue is created by interpolating a name within the following
```js
  .post(fmt('/1/projects/%s/queues/%s/messages', settings.projectId, payload["event-type"]))
// creating a this url '/1/projects/53446c02b83a0300090000ea/queues/Baked%20a%20cake/messages?oauth=8U4wEpN2Gi1qKMYTmwnVP3ZI8W0'

Baked a Cake will eventually be the name of the queue
```

The result is events stored within queues that can be processed by their own custom worker scripts or published to other endpoints for various x, y, z.

[https://github.com/Stephenitis/integrations/blob/c7304594c9d8261397f928f5e7588eb1c54c4eba/lib/iron-io/index.js#L37](https://github.com/Stephenitis/integrations/blob/c7304594c9d8261397f928f5e7588eb1c54c4eba/lib/iron-io/index.js#L37)

![segment io queues hud -- iron io 2014-04-08 16-30-44 2014-04-08 16-31-32](https://cloud.githubusercontent.com/assets/1712162/2650616/f2bfbd0c-bf75-11e3-80dc-e09e06301a87.png)

I was wondering what the best pattern to expose options users of this integration to send events to Iron.io via different queue naming/filtering strategies
- Event Type
- User Id
- Bucket (all into one queue)

right now I've only exposed the track function.