Choose a good 'on' criteria.

[jeffeb3]

Only checking on PRs or push is probably not sufficient. Especially for bugfix. I'd like to run bugfix periodically, like every 24 hours or so. But I am not sure I want that for all branches. But it isn't easy to copy the whole thing.

[jeffeb3]

I've changed it to run once/day. Not sure if I'm going to like that, since it will be broken for the near future.