John Brooking

I would make a commit and pull request for this, but I don't appear to have privs to create a branch, and I don't want to presume to do it...

Interestingly, I see that mjumbewu already [committed](https://github.com/openplans/shareabouts/commit/113e08a1e9d905cf3889056a0022a7065e52a929) a change to `app-requirements.txt` on May 23 for the raven change to 6.10.0, but the `requirements.txt` file was not similarly changed. (The `app-requirements.txt`...