Multiple Coveralls comments

[xavdid]

So I believe the source here is that it's running every time helper.rb is required (which is once for each of the ruby versions in .travis.yml).

There's some info in comments here: https://stackoverflow.com/questions/39357106/coveralls-report-runs-twice

Possible solution would be to only test it on the largest version (since it's mostly testing static code and won't differ per version), but that requires manual updates (lame). I was having trouble finding another repo that has coveralls comment after CI (which is weird, because it should be a common use case), but hopefully someone else has figured this out.