Fix bug with filtering by stack choices with commas
Fix bug with filtering by stack choices with commas

- Some of our stacks contain commas so we cannot use this as a delimeter. We
  need a more sophisticated regex.

pluralsight/guides-cms,paulocheque/guides-cms,paulocheque/guides-cms,pluralsight/guides-cms,paulocheque/guides-cms,pluralsight/guides-cms