When a bid is saved, add a watch for the issue

[groovecoder]

No description provided.

[groovecoder]

We should use GitHub PubSubHubbub: https://developer.github.com/v3/repos/hooks/#pubsubhubbub

[jgmize]

After doing some testing, it appears that in order to use the pubsubhubbub api we have to authenticate to github as a collaborator on the repo for the events we want to watch, not just any account.

[jgmize]

And by collaborator, I mean an admin. I tested this using a separate machine account I originally created for c9.io, and while I was able "subscribe" to issues on a repo that account created, but not one that it was merely able to push code to. For those, github responds with a 422.

[groovecoder]

So, considering the PuSH is out, I'll supersede this with a different issue: "Create cron job to poll status of all issues with bids."