Update OS X deployment target.
Update OS X deployment target.

TomoakiNagahara/UICKeyChainStore,kishikawakatsumi/UICKeyChainStore,v2dev/UICKeyChainStore,hanhailong/UICKeyChainStore,HSFGitHub/UICKeyChainStore,kishikawakatsumi/UICKeyChainStore,dezinezync/UICKeyChainStore,imjerrybao/UICKeyChainStore,Kingside/UICKeyChainStore,dleehr/UICKeyChainStore,Ninikitos/UICKeyChainStore,hulu001/UICKeyChainStore,royalwang/UICKeyChainStore,bigrpg/UICKeyChainStore,gauravds/UICKeyChainStore