Add gomoddirectives linter.

[ldez]

https://github.com/ldez/gomoddirectives

  gomoddirectives:
    # Allow local `replace` directives. Default is false.
    replace-local: false
    # List of allowed `replace` directives. Default is empty.
    replace-allow-list:
      - launchpad.net/gocheck
    # Allow to not explain why the version has been retracted in the `retract` directives. Default is false.
    retract-allow-no-explanation: false
    # Forbid the use of the `exclude` directives. Default is false.
    exclude-forbidden: false

[carnott-snap]

looks sane, meets the use cases we discussed; I have not tested this locally, but will trust the author/ci to assert its correctness. should we add some tests to verify anything, or are we trusting that is done in the upstream library?

[ldez]

@carnott-snap

should we add some tests to verify anything,

It's not possible with the current test system, but I added a lot of tests in my lib.

or are we trusting that is done in the upstream library?

FYI I'm a maintainer of golangci-lint, my code is on a public repo on GitHub, I added a lot of tests, I followed the guideline from the Go team to get the go.mod file, so yes I think that we trust me 😄

[bombsimon]

I trust you @ldez! ❤️