Unable to check if the user is authenticated.
Hi,
i tried to use the local strategy but with no luck. I keep getting `ctx.isAuthenticated()===false` in the `authMiddlweare`.

Here is my configuration:

``` js
function* authMiddlweare( next ) {
  debug( 'authMiddlweare' );

  if( this.isAuthenticated() ) { // ALWAYS FALSE HERE
    yield next;
  } else {
    var loginUrl = config.routes.publicArea.url( 'login' );
    this.redirect( loginUrl );
  }
}

passport.serializeUser( function( user, done ) {
  debug( 'Serializing %s(%s)', user.username, user.id );
  return done( null, user.id );
} );
passport.deserializeUser( function( id, done ) {
  debug( 'Deserializing (%s)', id );

  var User = config.models.user;

  User
  .findById( id )
  .execAsync()
  .then( function( user ) {
    if( !user )
      throw new Error( 'Unable to find the user for deserialization.' );

    return done( null, user );
  } )
  .catch( done );
} );

var strategyOptions = {
  failureRedirect: '/login'
};

var localStrategy = new LocalStrategy( function localStrategyCallback( username, password, done ) {
  debug( 'Local strategy check' );

  var User = config.models.user;

  User
  .findByUsername( username )
  .then( function( user ) {

    if( !user )
     throw new Error( 'No user with "'+username+'" found!' );

    debug( 'User %s(%s) found', user.username, user.id );

    if( !user.isPasswordValid( password ) )
     throw new Error( 'Invalid credentials!' );

    return done( null, user );
  } )
  .catch( done );
} );

passport.use( localStrategy );
```
