Give more comment abstraction

[siddharthkp]

pullRequest, commit_id can come from request payload, filename and position can come from sniffer.

function comment(pullRequest, commit_id, filename, position) {
    robocop.helpers.comment('review', {
        pullRequest: pullRequest,
        body: 'Not on my watch!',
        commit_id: commit_id,
        path: filename,
        position: position
    });
}
`