Include column numbers in report.

Summary

The CodeClimate report format, which GitLab adopted in a reduced form, supports two ways for specifying diagnostic error locations:

{
  "path": "path/to/file.css",
  "lines": {
    "begin": 13,
    "end": 14
  }
}

{
  "path": "path/to/file.css",
  "positions": {
    "begin": {
      "line": 3,
      "column": 10
    },
    "end": {
      "line": 4,
      "column": 12
    }
  }
}

The second form is richer, as it can include column numbers, which Pylint happens to be able to provide. pylint-gitlab will now use the second form.

More details on the specification in https://github.com/codeclimate/platform/blob/master/spec/analyzers/SPEC.md#locations.

GitLab supports both forms; see https://docs.gitlab.com/ci/testing/code_quality/#code-quality-report-format.

Test Plan

Change is covered by unit tests; expected outputs have been updated.