Got an older Macbook Pro (2.1) which I used for developing for the iOS about a year ago. It's running 10.6 at the moment. Just started it up to try out some more iOS development and noticed I require 10.7 for the latest Xcode. So I went online to try find it, but all I can find now is Mountain Lion which if I understand is not compatible with my hardware. Is there a way for me to upgrade from 10.6 to 10.7? Preferable with the AppStore.