[travis] add debian buster

[arthurzenika]

PR progress checklist (to be filled in by reviewers)

• Changes to documentation are appropriate (or tick if not required)
• Changes to tests are appropriate (or tick if not required)
• Reviews completed

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What type of PR is this?

Primary type

• [build] Changes related to the build system
• [chore] Changes to the build process or auxiliary tools and libraries such as documentation generation
• [ci] Changes to the continuous integration configuration
• [feat] A new feature
• [fix] A bug fix
• [perf] A code change that improves performance
• [refactor] A code change that neither fixes a bug nor adds a feature
• [revert] A change used to revert a previous commit
• [style] Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc.)

Secondary type

• [docs] Documentation changes
• [test] Adding missing or correcting existing tests

Does this PR introduce a BREAKING CHANGE?

No.

Related issues and/or pull requests

Describe the changes you're proposing

Pillar / config required to test the proposed changes

Debug log showing how the proposed changes work

Documentation checklist

• Updated the README (e.g. Available states).
• Updated pillar.example.

Testing checklist

• Included in Kitchen (i.e. under state_top).
• Covered by new/existing tests (e.g. InSpec, Serverspec, etc.).
• Updated the relevant test pillar.

Additional context

[myii]

@arthurlogilab We're using pre-salted images for testing across 60+ formulas now. They're a much faster and a more efficient use of our Travis concurrency (only 3 jobs across the whole org). So please take the definitions from the template-formula, to use those instead.

Or perhaps we can implement semantic-release for this formula. The process automatically configures all of the pre-salted images. What do you think?

[arthurzenika]

@myii semantic-release for this formula would be great !

Is there an easy way to take the sane defaults in template-formula, apply them to this formula (or another) and create a merge request ?

[myii]

... semantic-release for this formula would be great !

OK, I'll try to prepare something fairly soon.

Is there an easy way to take the sane defaults in template-formula, apply them to this formula (or another) and create a merge request ?

We've been using the ssf-formula to keep everything synchronised across all of these formulas. An example PR for adding another formula to be managed:

• https://github.com/myii/ssf-formula/pull/101/files

It's proved to be fairly robust (except for the Git scripts which will need to be improved). It may be difficult to get familiar with for other contributors, though. It's quite dense.

[javierbertoli]

@arthurlogilab, I think I fixed all the issues with this PR (running local tests now), Are you OK if I push here?

[arthurzenika]

@javierbertoli sure!