Express empty req.session.grant 
config:

``` javascript
{
    "server": {
        "protocol": "http",
        "host": "localhost:3000"
    },
    "intuit": {
        "request_url": "https://oauth.intuit.com/oauth/v1/get_request_token",
        "authorize_url": "https://appcenter.intuit.com/Connect/Begin",
        "access_url": "https://oauth.intuit.com/oauth/v1/get_access_token",
        "oauth": 1,
        "key": "mykey",
        "secret": "mysecret",
        "callback": "/api/connect/intuit",
        "custom_params": {
            "datasources": {
                "quickbooks": true,
                "payments" : false
            }
        }
    }
}
```

app.js

``` javascript
var Session = require('express-session')
    , session = Session({secret: 'very secret', resave: true, saveUninitialized: true})
    , Grant = require('grant-express')
    , grant = new Grant(config.connect);

app.use(session);
app.use(grant);

app.get('/api/connect/intuit', function (req, res) {
    console.log('----------------------------------------------------');
    console.log(req);
    console.log('----------------------------------------------------');
});
```

I'm getting `{"error":"Grant: missing session or misconfigured provider"}`. 
When logging `req.session` in `grant/lib/consumer/express.js:98` I get:

``` javascript
{ cookie: 
   { path: '/',
     _expires: null,
     originalMaxAge: null,
     httpOnly: true } }
```

So it seems like the grant details aren't being updated to the session.

I was using this example as reference: https://github.com/simov/grant/tree/master/example/express

What am I missing?
