Improve Docker tags

[markhobson]

We currently support the following tags:

• latest (jdk-8/Dockerfile)
• jdk-11 (jdk-11/Dockerfile)
• jdk-16 (jdk-16/Dockerfile)

These should become:

• jdk-8 (jdk-8/Dockerfile)
• jdk-11 (jdk-11/Dockerfile)
• jdk-16, latest (jdk-16/Dockerfile)

This requires:

1. Multiple Docker tags per build, which doesn't appear to be working in Docker Hub. Using a post push hook may be a suitable workaround.
2. Switching latest from jdk-8 to jdk-16. This will break users currently reliant upon this tag.

[markhobson]

It appears that Docker Hub does now support multiple tags per build. I've added jdk-8 as an alias for latest which is jdk-8/Dockerfile.

I'll update the docs to ask those using latest to start using jdk-8 instead, so we can switch latest to jdk-15 at a later date.

[arturds]

you can add a chrome version on tag too, since last update many of my testes start to fail

[markhobson]

@arturds You can see #2 for a previous discussion about tagging against specific Chrome versions. In summary, we don't since Chrome updates automatically and this image tries to reflect this.

[amony-ot]

Hi Mark,

When i'm using your chrome images its throwing an timeout exception. Even i selected all three java versions.

ChromeDriver was started successfully.
[1617639057.803][SEVERE]: Timed out receiving message from renderer: 600.000

[markhobson]

Hi @amony-ot, this sounds similar to #20 but I'm not seeing these messages any more. Could you raise a new issue with more details please?

[amony-ot]

It worked On Jan 15, but the same image is not working recently. When i update it to Firefox its working without any issues. Not sure whether the latest update to 89 version causing this issue.

[markhobson]

@amony-ot It's certainly a Chrome issue, so you won't experience it with Firefox. Could you raise a new issue with more details, rather than comment on this unrelated one please?

[markhobson]

I've now switched latest to point to jdk-16 rather than jdk-8. Please update any image references that need to be fixed at JDK 8 to use the Docker tag jdk-8 - I've added a note to the README.