[LocalPod] Store the platform.
[LocalPod] Store the platform.

The specification class only stores the active platform symbol.

ashfurrow/CocoaPods,orta/CocoaPods,mglidden/CocoaPods,Ashton-W/CocoaPods,0xced/CocoaPods,mglidden/CocoaPods,segiddins/CocoaPods,vivekshukla-mob-ibtech/Repository,mglidden/CocoaPods