use mongo-store in express session (see

4409329271bafd68e931d1d13e5519109a9a3c8e of chat-example)

src/server/index.coffee

@@ -5,6 +5,7 @@ gzippo = require 'gzippo'
 derby = require 'derby'
 app = require '../app'
 serverError = require './serverError'
+MongoStore = require('connect-mongo')(express)
 
 ## RACER CONFIGURATION ##
 
@@ -71,6 +72,7 @@ expressApp
   .use(store.sessionMiddleware
     secret: process.env.SESSION_SECRET || 'YOUR SECRET HERE'
     cookie: {maxAge: ONE_YEAR}
+    store: new MongoStore(db: 'habitrpg')
   )
 
   # Adds req.getModel method