[feature/carthage] Update Travis to use Xcode 8
[feature/carthage] Update Travis to use Xcode 8

carambalabs/SugarRecord,carambalabs/SugarRecord,gitdoapp/SugarRecord,SwiftReactive/SugarRecord,SugarTeam/SugarRecord,SwiftReactive/SugarRecord,SwiftReactive/SugarRecord,pepibumur/SugarRecord,gitdoapp/SugarRecord,SugarTeam/SugarRecord,SugarRecord/SugarRecord,pepibumur/SugarRecord,SugarRecord/SugarRecord,gitdoapp/SugarRecord,SugarTeam/SugarRecord