in api/src/main/scala/com/gu/adapters/store/Store.scala [198:207]
def copy(
fromBucket: String,
fromKey: String,
toBucket: String,
toKey: String
): Either[Error, Unit] = {
val request = new CopyObjectRequest(fromBucket, fromKey, toBucket, toKey)
handleIoErrors(client.copyObject(request))
}