Leave a comment if no issues found

[tomjn]

If no PHPCS issues are found, no comments are left on the PR, which can leave users unsure if it's ran or not. Leaving a comment would remove the uncertainty

[gudmdharalds]

This is something vip-go-ci did at first, but it was later discussed and decided that it would be enough to leave a green check-mark on the build to indicate that everything was good. Most users seem to be satisfied with this.

I do agree that a comment might be a good idea. I would like to see some strong arguments for introducing it though. Let me know if you have anything in mind.

[davidsword]

I think this would be a good idea. +1

The visual cue of the comment is more obvious than "All checks have passed", and it gives a nice pat on the back to the author that things look good.

[gudmdharalds]

With the optional configuration now in place, we could introduce this and allow users to turn the feature off.

[gudmdharalds]

This is resolved in #246.