Add faillint as a linter

[mcristina422]

Add https://github.com/fatih/faillint/ as a linter.

Faillint is a simple Go linter that fails when a specific set of import paths or exported path's functions, constant, vars or types are used. It's meant to be used in CI/CD environments to catch rules you want to enforce in your projects.

[jirfag]

Hi, we already have modguard and depguard for black/white listing imports. Maybe some of our linters also support func/const/var checking?

[sagar23sj]

I am first time contributor to golangci-lint and would like to contribute to this issue. Can anyone help me understand what exactly is needed from this issue? If someone help me understand, I will start working on it right away. Thanks

[Antonboom]

Covered by:

1. depguard
2. gomodguard
3. forbidigo

@ldez, I think we can close this issue.

[ldez]

I agree.