Just curious if you have any thoughts on using an images file like this vs trying to parse the image names from Rackspace? I hadn't been able to convince myself fully on using a parser that'd be more likely to fail or a list subject to changing image IDs (e.g. when the Ubuntu 12.10 image ID [changed](https://github.com/RoboticCheese/kitchen-rackspace/commit/9d8e1a1e6bfba9956e6009ad4617127c8af2dc4b) recently). Thanks!