[rake] Re-enable specs during release, but add env var to disable.
[rake] Re-enable specs during release, but add env var to disable.

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