Version 3.18.6

• Aws\ApiGateway - Added support for additional field on Integration to
  control passthrough behavior
• Aws\CloudTrail - Deprecates the SnsTopicName field in favor of SnsTopicArn
• Aws\Ecs - Added support for non-comprehensive logDriver enum
• Aws\Kms - Added support for "pro-lockout" flag
• Aws\S3 - Amazon S3 Added a new list type to list objects in buckets
  with a large number of delete markers