Switch travis to xcode 7.3
Switch travis to xcode 7.3

Brightify/Cuckoo,Brightify/Cuckoo,powerfolder/Cuckoo,SwiftKit/Cuckoo,Monnoroch/Cuckoo,powerfolder/Cuckoo,mrgerych/Cuckoo,Brightify/Cuckoo,SwiftKit/Cuckoo,Monnoroch/Cuckoo,Monnoroch/Cuckoo,mrgerych/Cuckoo,SwiftKit/Cuckoo,Monnoroch/Cuckoo,mrgerych/Cuckoo,powerfolder/Cuckoo,Monnoroch/Cuckoo