Ubuntu without JDK, additional latest Ubuntu LTS and JDK11

[Nicklas2751]

What does this PR do?

I moved the JDK installation from the ubuntu base image to the ubuntu_jdkX images to make it possible to create images with other JDK versions based on the same base image. I also added a new ubuntu base image called ubuntu_lts with the latest lts version (18.04) but this is only a workaround until #214 got merged. The ubuntu_lts image is the base for the new ubuntu_jdk11 image I also added.

After my changes i builded all images with the build.sh via gitlab-ci on a private gitlab instance to check if all images build.

What issues does this PR fix or reference?

• Fixing #231

Previous behavior

• The base ubuntu image came with java installed.
• No image for JDK 11.
• No image with latest ubuntu lts

New behavior

• Moved JDK installation from ubuntu base image to the ubuntu_jdkX images
• Added new ubuntu base image (ubuntu_lts) with the latest ubuntu lts version
• Added image for JDK 11 with ubuntu (ubuntu_jdk11)

Tests written?

No automatic test but builded all images with gitlab-ci on a private gitlab instance.

Docs updated?

No

[Nicklas2751]

I saw that I have to sign the ECA and signed it now. ;)

[dneary]

@eivantsov Can you review this proposal, please?

[ghost]

This PR will break all stack images for Che. We need Java in all of them and that is why it is installed in a base image from which other images inherit.

Also, @dneary I think we should not expand our ready to go stacks for several reasons: 1. maintenance 2. Che 7 coming soon

[dneary]

Thanks Eugene.

Why do we need Java in every stack image?

Also: I was not suggesting that this patch was ready to merge - I just noticed it had not yet been reviewed, and thought you would be able to help, and provide guidance to @Nicklas2751 about what to change.