define lint fixer task

consider this snippet inside .golangci.yml

```
issues:
  max-issues-per-linter: 0
  max-same-issues: 0
  fix: false
```

Looks like there is a fix option. I wonder if we can override this when running golangci-lint on the command line interactively. Rather, I would like to create a new task, perhaps fix, which could be used to automatically fix up lint errors.
