Invoke vendoring script on CI

[hroncok]

Is your feature request related to a problem? Please describe.

I'm always frustrated when I try to update the vendoring script but I'm hit by unrelated issues.

Describe the solution you'd like

This could be solved by having the vendoring script being run as part of the Continues Integration (Travis CI e.g. has daily cron as well).

Describe alternatives you've considered

Prove that the vendoring script is always reproducible.

Additional context

#2426 (comment)

[techalchemy]

I am +1 on this as well, have been meaning to do this but yeah, it's on the list. You know how it is. I have to test it before every release and it's always basically what you experienced.

[hroncok]

I don't see Travis CI enabled. Would a PR with this being run on Travis be accepted?

[erinxocon]

@hroncok We use buildkite for unix testing, and VSTS for windows testing. We'll have to figure out how to integrate them on those platforms.

[techalchemy]

I just pr'ed it (we also use appveyor currently)

We really need to sort out how to make buildkite publicly visible...

[uranusjr]

For the vendoring process itself, would it a good idea to use a bot? I know there’re already mentions of this idea, we can use it to make sure a PR provides news fragments, and (if needed) generate patch files.

[techalchemy]

I’d love that. Would need to get time to set this up