Upgrade to express 4.8.5 and cors 2.4.1.
Improve getMiddleware.
Merge pull request #181 from mozilla-services/go-express-4

Upgrade to express 4.8.5 and cors 2.4.1.
Don't import request in loop/index.js
First implementation of FxA implementation with OAuth
Update the configuration with the right values.
Do not genrate the OAuth state if it already exists
Update the code after @ckarlof and @vladikoff review
Plug fxa-oauth in the routes
Move the session endpoint into a new route
Add tests and update the code accordingly
Update the code to the new Express 4.0 standards