MongoHQ overrides env

This bit us again today...MongoHQ changed the location of our database, and since we're hand-crafting our Mongo connections we had a 5 hour outage on CSOL. Not that it's an enormous deal, but it still caused pages and texts and stuff. So, worth the ten minutes to fix it.

This branch has been deployed to CSOL production, openbadges badges production and CEM production just in case MongoHQ decides to shift our databases around again (a perfectly reasonable thing to do, honestly).

:christmas_tree: :santa: