Revert "[travis] Simplify config and use os:osx"
Revert "[travis] Simplify config and use os:osx"

This reverts commit 2e343e8f8002d9c77861dc7a8f18e991966fbf87.

ashfurrow/CocoaPods,mglidden/CocoaPods,mglidden/CocoaPods,mglidden/CocoaPods