Update build script to use iOS 10.3 simulator

scripts/build.sh

@@ -4,4 +4,4 @@ xcodebuild -project SwiftyStoreKit.xcodeproj -target SwiftyStoreKit_iOS
 xcodebuild -project SwiftyStoreKit.xcodeproj -target SwiftyStoreKit_macOS
 xcodebuild -project SwiftyStoreKit.xcodeproj -target SwiftyStoreKit_tvOS
 
-xcodebuild test -project SwiftyStoreKit.xcodeproj -scheme SwiftyStoreKitTests -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone 6,OS=10.0'
+xcodebuild test -project SwiftyStoreKit.xcodeproj -scheme SwiftyStoreKitTests -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone 6,OS=10.3'