in core/src/main/scala/com/gu/conf/ConfigurationLocation.scala [21:26]
override def load(credentials: => AwsCredentialsProvider): Config = {
val aggregatedConfig = locations.map(_.load(credentials)).foldLeft(ConfigFactory.empty()) {
case (agg, loadedConfig) => agg.withFallback(loadedConfig)
}
aggregatedConfig.resolve()
}