CocoaPods/Specs — pull request #5750 by DanBrooker (2013-11-27 22:54:36+00:00)
Title: Specify ios and osx minimum version without clobbering

Shouldn't be setting spec.platform twice
Changes to set deployment_target per platform as per [wiki](https://github.com/CocoaPods/CocoaPods/wiki/The-podspec-format#platform-attributes)