Changing status of Pycon 2016 Education Summits causes an error.

[hatlas]

Edusummits are now showing up properly on Edusummit page (see #544), but changing their status (ie., "not Yet reviewed", "In Kittendome", etc.) on review page (https://staging-pycon.python.org/2016/reviews/section/edusummit/) leads to the following error:

Oops, we've had a problem on the server. The web team have been informed and will be looking into it but if you have any questions, don't hesitate to email:

This only occurs with edusummits, not other types of proposal.

[dpoirier]

@hatlas The fix for this is deployed to staging for QA.

[hatlas]

Passes QA; here's a couple of edusummit proposals with successfully changed statuses.