Sync Comments from PivotalTracker over to GitHub issues

This PR adds a few things:
1) From my testing, the feature for closing a github issue when a PT story closes wasn't working, because the parsing code for the PT API responses wasn't correct anymore.  So, I updated it so that feature works again.

2) I added the ability to syndicate a PT comment over to the GitHub bug.  This is now done via the "issueHandle" function, which will decide whether to call "closeIssue" or "addIssueComment" based on the payload from PT.

3) I added a configuration file so that either of these features can be turned on or off, and by default they're both on.  I also added a default route which shows these values, so that they can be inspected via the web if one wanted.

I will take no offense if you want some of these features reworked before accepting them - definitely open to feedback.  Also happy to rebase if you want this to come through as a single commit.  There's a long commit history here because I couldn't test PivotalTracker callbacks without deploying live.