title: Passport can't add parameters for local authentification
body: <p>I am using passport local authentification with this tutorial:
  <a href="https://scotch.io/tutorials/easy-node-authentication-setup-and-local" rel="nofollow">https://scotch.io/tutorials/easy-node-authentication-setup-and-local</a></p>
  
  <p>It work's fine but I wan't to add some parameters to my user like his firs name and last name in my mongoldb database. I can't figure out how I can do with this function because it's a callback and I can't pass somme parameters after the <code>done</code></p>
  
  <pre><code>    passport.use('local-signup', new LocalStrategy({
                  // by default, local strategy uses username and password, we will override with email
                  usernameField : 'email',
                  passwordField : 'password',
                  lastnameField : 'lastname', // here I added this field
                  firstnameField : 'first name', // here I added this field
              },
              function(req, email, password, done) {
  
                  // asynchronous
                  // User.findOne wont fire unless data is sent back
                  process.nextTick(function() {
  
                      // find a user whose email is the same as the forms email
                      // we are checking to see if the user trying to login already exists
                      User.findOne({ 'local.email' :  email }, function(err, user) {
                          // if there are any errors, return the error
                          if (err)
                              return done(err);
  
                          // check to see if theres already a user with that email
                          if (user) {
                              return done(null, false, req.flash('signupMessage', 'That email is already taken.'));
                          } else {
  
                              // if there is no user with that email
                              // create the user
                              var newUser            = new User();
  
                              // set the user's local credentials
                              newUser.local.email    = email;
                              newUser.local.password = newUser.generateHash(password);
  // here I want to save my field :
                              newUser.local.lastname = lastname;
                              newUser.local.firstname = firstname;
  
                              // save the user
                              newUser.save(function(err) {
                                  if (err)
                                      throw err;
                                  return done(null, newUser);
                              });
                          }
  
                      });
  
                  });
              }));
  </code></pre>
  
  <p>Can you help me please ?</p>