GH-164: Fix `ZipTransformer` `deleteFile` mode

[artembilan]

Fixes GH-164 (https://github.com/spring-projects/spring-integration-extensions/issues/164)

• Move deleteFile logic to the end of of ZipTransformer#doZipTransform()
• Add deleteFile = true for the ZipTransformerTests
• Add <request-handler-advice-chain> to the transformers XSD definitions
• Upgrade to Gradle 3.0
• Upgrade dependencies

[garyrussell]

Merged as 9a13e41d9607517f978afdca4fa55f11a925ab4e