update passport when it gets stable

[bjrmatos]

there is an audit report for passport but we can not update it because its 0.6.0 release has some issues. when it is fixed we should update our dep and code.

Relevant links:

• Sessions do not always have regenerate() and save() cauing a fault jaredhanson/passport#904
• req.session.regenerate is not a function since upgrade to 0.6.0 jaredhanson/passport#907
• Callback is not a function on logout jaredhanson/passport#913 (comment) (req.logout now needs a callback, so we should add similar code when needed)