Build and run against latest SDK
Build and run against latest SDK

Adds separate variables for build and runtime SDK to Rakefile

pivotal/PivotalCoreKit,idoru/PivotalCoreKit,joemasilotti/PivotalCoreKit,gudatcomputers/PivotalCoreKit,mjstallard/PivotalCoreKit,jfuchs/PivotalCoreKit,joemasilotti/PivotalCoreKit,gudatcomputers/PivotalCoreKit,idoru/PivotalCoreKit,briancroom/PivotalCoreKit,pivotaltracker/PivotalCoreKit,jfuchs/PivotalCoreKit