[integration-testing.xml]: listings are dated

[duncdrum]

Describe the problem
The listings still use oracleJdk and Xenial default images, we should updated them in light of #519 to use openJDK and a more recent linux distro

The final javascript code listing isn't properly linted, not sure yet why.

Please provide the following

• exist-db version: 5.3.0-SNAPSHOT
• documentation version: 5.2.1-SNAPSHOT